# OpenSSL changelog

> The TLS/SSL and general-purpose cryptography toolkit.

- Vendor: OpenSSL Project
- Category: Developer Tools
- Official site: https://www.openssl.org
- Tracked by: What's New (https://whatsnew.fyi/product/openssl)
- Harvested from: GitHub (openssl/openssl)
- Entries below: 10 (newest first)

What's New is an index, not a publisher: every entry below links to the vendor's own release notes, which are the authoritative source. Entries are labelled where they are hand-curated sample data, pre-releases, or drawn from a secondary source such as a developer blog.

## Releases

### openssl-3.0.21 — OpenSSL 3.0.21

- Date: 2026-06-09
- Version: openssl-3.0.21
- Original notes: https://github.com/openssl/openssl/releases/tag/openssl-3.0.21
- Permalink: https://whatsnew.fyi/product/openssl/releases/openssl-3.0.21

- **security** — Fix heap use-after-free in PKCS7_verify()
- **security** — Fix CMS AuthEnvelopedData processing that may accept forged messages
- **security** — Fix AES-OCB IV ignored on EVP_Cipher() path
- **security** — Fix possible heap buffer overflow in ASN.1 multibyte string conversion
- **security** — Fix out-of-bounds read in CMS password-based decryption
- **security** — Fix heap buffer over-read in ASN.1 content parsing
- **security** — Fix possible NULL dereference in password-based CMS decryption
- **security** — Fix FFC-DH peer validation that uses attacker-supplied q
- **security** — Fix incorrect tag processing for empty messages in AES-GCM-SIV and AES-SIV modes

OpenSSL 3.0.21 is a security patch release.  The most severe CVE fixed
in this release is High.

This release incorporates the following bug fixes and mitigations:

  * Fixed heap use-after-free in `PKCS7_verify()`.
    ([CVE-2026-45447])

  * Fixed CMS `AuthEnvelopedData` processing may accept forged messages.
    ([CVE-2026-34182])

  * Fixed AES-OCB IV ignored on `EVP_Cipher()` path.
    ([CVE-2026-45445])

  * Fixed possible heap buffer overflow in ASN.1 multibyte string conversion.
    ([CVE-2026-7383])

  * Fixed out-of-bounds read in CMS password-based decryption.
    ([CVE-2026-9076])

  * Fixed heap buffer over-read in ASN.1 content parsing.
    ([CVE-2026-34180])

  * Fixed possible NULL dereference in password-dased CMS decryption.
    ([CVE-2026-42766])

  * Fixed FFC-DH peer validation uses attacker-supplied `q`.
    ([CVE-2026-42770])

  * Fixed incorrect tag processing for empty messages in AES-GCM-SIV
    and AES-SIV modes.
    ([CVE-2026-45446])

[CVE-2026-45447]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-45447
[CVE-2026-34182]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-34182
[CVE-2026-45445]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-45445
[CVE-2026-7383]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-7383
[CVE-2026-9076]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-9076
[CVE-2026-34180]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-34180
[CVE-2026-42766]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-42766
[CVE-2026-42770]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-42770
[CVE-2026-45446]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-45446

### openssl-3.4.6 — OpenSSL 3.4.6

- Date: 2026-06-09
- Version: openssl-3.4.6
- Original notes: https://github.com/openssl/openssl/releases/tag/openssl-3.4.6
- Permalink: https://whatsnew.fyi/product/openssl/releases/openssl-3.4.6

- **security** — Fixed heap use-after-free in PKCS7_verify()
- **security** — Fixed CMS AuthEnvelopedData processing that may accept forged messages
- **security** — Fixed unbounded memory growth in the QUIC PATH_CHALLENGE handler
- **security** — Fixed AES-OCB IV ignored on EVP_Cipher() path
- **security** — Fixed possible heap buffer overflow in ASN.1 multibyte string conversion
- **security** — Fixed out-of-bounds read in CMS password-based decryption
- **security** — Fixed heap buffer over-read in ASN.1 content parsing
- **security** — Fixed PKCS#12 files with PBMAC1 that are accepted with short HMAC keys
- **security** — Fixed possible NULL dereference in password-based CMS decryption
- **security** — Fixed multi-RecipientInfo Bleichenbacher Oracle in CMS_decrypt() and PKCS7_decrypt()
- **security** — Fixed trust anchor substitution via cert/issuer typo in CMP rootCaKeyUpdate
- **security** — Fixed FFC-DH peer validation that uses attacker-supplied q
- **security** — Fixed incorrect tag processing for empty messages in AES-GCM-SIV and AES-SIV modes

OpenSSL 3.4.6 is a security patch release.  The most severe CVE fixed
in this release is High.

This release incorporates the following bug fixes and mitigations:

  * Fixed heap use-after-free in `PKCS7_verify()`.
    ([CVE-2026-45447])

  * Fixed CMS `AuthEnvelopedData` processing may accept forged messages.
    ([CVE-2026-34182])

  * Fixed unbounded memory growth in the QUIC `PATH_CHALLENGE` handler.
    ([CVE-2026-34183])

  * Fixed AES-OCB IV ignored on `EVP_Cipher()` path.
    ([CVE-2026-45445])

  * Fixed possible heap buffer overflow in ASN.1 multibyte string conversion.
    ([CVE-2026-7383])

  * Fixed out-of-bounds read in CMS password-based decryption.
    ([CVE-2026-9076])

  * Fixed heap buffer over-read in ASN.1 content parsing.
    ([CVE-2026-34180])

  * Fixed PKCS#12 files with PBMAC1 are accepted with short HMAC keys.
    ([CVE-2026-34181])

  * Fixed possible NULL dereference in password-dased CMS decryption.
    ([CVE-2026-42766])

  * Fixed multi-`RecipientInfo` Bleichenbacher Oracle in `CMS_decrypt()`
    and `PKCS7_decrypt()`.
    ([CVE-2026-42768])

  * Fixed trust anchor substitution via `cert`/`issuer` typo in CMP
    `rootCaKeyUpdate`.
    ([CVE-2026-42769])

  * Fixed FFC-DH peer validation uses attacker-supplied `q`.
    ([CVE-2026-42770])

  * Fixed incorrect tag processing for empty messages in AES-GCM-SIV
    and AES-SIV modes.
    ([CVE-2026-45446])

[CVE-2026-45447]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-45447
[CVE-2026-34182]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-34182
[CVE-2026-34183]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-34183
[CVE-2026-45445]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-45445
[CVE-2026-7383]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-7383
[CVE-2026-9076]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-9076
[CVE-2026-34180]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-34180
[CVE-2026-34181]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-34181
[CVE-2026-42766]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-42766
[CVE-2026-42768]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-42768
[CVE-2026-42769]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-42769
[CVE-2026-42770]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-42770
[CVE-2026-45446]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-45446

### openssl-3.5.7 — OpenSSL 3.5.7

- Date: 2026-06-09
- Version: openssl-3.5.7
- Original notes: https://github.com/openssl/openssl/releases/tag/openssl-3.5.7
- Permalink: https://whatsnew.fyi/product/openssl/releases/openssl-3.5.7

- **security** — Fixed heap use-after-free in PKCS7_verify()
- **security** — Fixed CMS AuthEnvelopedData processing may accept forged messages
- **security** — Fixed unbounded memory growth in the QUIC PATH_CHALLENGE handler
- **security** — Fixed NULL pointer dereference in QUIC server initial packet handling
- **security** — Fixed AES-OCB IV ignored on EVP_Cipher() path
- **security** — Fixed possible heap buffer overflow in ASN.1 multibyte string conversion
- **security** — Fixed out-of-bounds read in CMS password-based decryption
- **security** — Fixed heap buffer over-read in ASN.1 content parsing
- **security** — Fixed PKCS#12 files with PBMAC1 are accepted with short HMAC keys
- **security** — Fixed possible NULL dereference in password-based CMS decryption
- **security** — Fixed NULL pointer dereference in CRMF EncryptedValue decryption
- **security** — Fixed multi-RecipientInfo Bleichenbacher Oracle in CMS_decrypt() and PKCS7_decrypt()
- **security** — Fixed trust anchor substitution via cert/issuer typo in CMP rootCaKeyUpdate
- **security** — Fixed FFC-DH peer validation uses attacker-supplied q
- **security** — Fixed incorrect tag processing for empty messages in AES-GCM-SIV and AES-SIV modes

OpenSSL 3.5.7 is a security patch release.  The most severe CVE fixed
in this release is High.

This release incorporates the following bug fixes and mitigations:

  * Fixed heap use-after-free in `PKCS7_verify()`.
    ([CVE-2026-45447])

  * Fixed CMS `AuthEnvelopedData` processing may accept forged messages.
    ([CVE-2026-34182])

  * Fixed unbounded memory growth in the QUIC `PATH_CHALLENGE` handler.
    ([CVE-2026-34183])

  * Fixed NULL pointer dereference in QUIC server initial packet handling.
    ([CVE-2026-42764])

  * Fixed AES-OCB IV ignored on `EVP_Cipher()` path.
    ([CVE-2026-45445])

  * Fixed possible heap buffer overflow in ASN.1 multibyte string conversion.
    ([CVE-2026-7383])

  * Fixed out-of-bounds read in CMS password-based decryption.
    ([CVE-2026-9076])

  * Fixed heap buffer over-read in ASN.1 content parsing.
    ([CVE-2026-34180])

  * Fixed PKCS#12 files with PBMAC1 are accepted with short HMAC keys.
    ([CVE-2026-34181])

  * Fixed possible NULL dereference in password-dased CMS decryption.
    ([CVE-2026-42766])

  * Fixed NULL pointer dereference in CRMF `EncryptedValue` decryption.
    ([CVE-2026-42767])

  * Fixed multi-`RecipientInfo` Bleichenbacher Oracle in `CMS_decrypt()`
    and `PKCS7_decrypt()`.
    ([CVE-2026-42768])

  * Fixed trust anchor substitution via `cert`/`issuer` typo in CMP
    `rootCaKeyUpdate`.
    ([CVE-2026-42769])

  * Fixed FFC-DH peer validation uses attacker-supplied `q`.
    ([CVE-2026-42770])

  * Fixed incorrect tag processing for empty messages in AES-GCM-SIV
    and AES-SIV modes.
    ([CVE-2026-45446])

[CVE-2026-45447]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-45447
[CVE-2026-34182]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-34182
[CVE-2026-34183]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-34183
[CVE-2026-42764]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-42764
[CVE-2026-45445]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-45445
[CVE-2026-7383]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-7383
[CVE-2026-9076]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-9076
[CVE-2026-34180]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-34180
[CVE-2026-34181]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-34181
[CVE-2026-42766]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-42766
[CVE-2026-42767]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-42767
[CVE-2026-42768]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-42768
[CVE-2026-42769]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-42769
[CVE-2026-42770]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-42770
[CVE-2026-45446]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-45446

### openssl-3.6.3 — OpenSSL 3.6.3

- Date: 2026-06-09
- Version: openssl-3.6.3
- Original notes: https://github.com/openssl/openssl/releases/tag/openssl-3.6.3
- Permalink: https://whatsnew.fyi/product/openssl/releases/openssl-3.6.3

- **security** — Fixed heap use-after-free in PKCS7_verify()
- **security** — Fixed CMS AuthEnvelopedData processing that may accept forged messages
- **security** — Fixed unbounded memory growth in the QUIC PATH_CHALLENGE handler
- **security** — Fixed double-free when checking OCSP stapled response
- **security** — Fixed NULL pointer dereference in QUIC server initial packet handling
- **security** — Fixed AES-OCB IV ignored on EVP_Cipher() path
- **security** — Fixed possible heap buffer overflow in ASN.1 multibyte string conversion
- **security** — Fixed out-of-bounds read in CMS password-based decryption
- **security** — Fixed heap buffer over-read in ASN.1 content parsing
- **security** — Fixed PKCS#12 files with PBMAC1 that are accepted with short HMAC keys
- **security** — Fixed NULL dereference in certificate verification with OCSP Checking
- **security** — Fixed possible NULL dereference in password-based CMS decryption
- **security** — Fixed NULL pointer dereference in CRMF EncryptedValue decryption
- **security** — Fixed multi-RecipientInfo Bleichenbacher Oracle in CMS_decrypt() and PKCS7_decrypt()
- **security** — Fixed trust anchor substitution via cert/issuer typo in CMP rootCaKeyUpdate
- **security** — Fixed FFC-DH peer validation uses attacker-supplied q
- **security** — Fixed incorrect tag processing for empty messages in AES-GCM-SIV and AES-SIV modes

OpenSSL 3.6.3 is a security patch release.  The most severe CVE fixed
in this release is High.

This release incorporates the following bug fixes and mitigations:

  * Fixed heap use-after-free in `PKCS7_verify()`.
    ([CVE-2026-45447])

  * Fixed CMS `AuthEnvelopedData` processing may accept forged messages.
    ([CVE-2026-34182])

  * Fixed unbounded memory growth in the QUIC `PATH_CHALLENGE` handler.
    ([CVE-2026-34183])

  * Fixed double-free when checking OCSP stapled response.
    ([CVE-2026-35188])

  * Fixed NULL pointer dereference in QUIC server initial packet handling.
    ([CVE-2026-42764])

  * Fixed AES-OCB IV ignored on `EVP_Cipher()` path.
    ([CVE-2026-45445])

  * Fixed possible heap buffer overflow in ASN.1 multibyte string conversion.
    ([CVE-2026-7383])

  * Fixed out-of-bounds read in CMS password-based decryption.
    ([CVE-2026-9076])

  * Fixed heap buffer over-read in ASN.1 content parsing.
    ([CVE-2026-34180])

  * Fixed PKCS#12 files with PBMAC1 are accepted with short HMAC keys.
    ([CVE-2026-34181])

  * Fixed NULL dereference in certificate verification with OCSP Checking.
    ([CVE-2026-42765])

  * Fixed possible NULL dereference in password-dased CMS decryption.
    ([CVE-2026-42766])

  * Fixed NULL pointer dereference in CRMF `EncryptedValue` decryption.
    ([CVE-2026-42767])

  * Fixed multi-`RecipientInfo` Bleichenbacher Oracle in `CMS_decrypt()`
    and `PKCS7_decrypt()`.
    ([CVE-2026-42768])

  * Fixed trust anchor substitution via `cert`/`issuer` typo in CMP
    `rootCaKeyUpdate`.
    ([CVE-2026-42769])

  * Fixed FFC-DH peer validation uses attacker-supplied `q`.
    ([CVE-2026-42770])

  * Fixed incorrect tag processing for empty messages in AES-GCM-SIV
    and AES-SIV modes.
    ([CVE-2026-45446])

[CVE-2026-45447]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-45447
[CVE-2026-34182]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-34182
[CVE-2026-34183]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-34183
[CVE-2026-35188]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-35188
[CVE-2026-42764]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-42764
[CVE-2026-45445]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-45445
[CVE-2026-7383]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-7383
[CVE-2026-9076]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-9076
[CVE-2026-34180]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-34180
[CVE-2026-34181]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-34181
[CVE-2026-42765]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-42765
[CVE-2026-42766]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-42766
[CVE-2026-42767]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-42767
[CVE-2026-42768]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-42768
[CVE-2026-42769]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-42769
[CVE-2026-42770]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-42770
[CVE-2026-45446]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-45446

### openssl-4.0.1 — OpenSSL 4.0.1

- Date: 2026-06-09
- Version: openssl-4.0.1
- Original notes: https://github.com/openssl/openssl/releases/tag/openssl-4.0.1
- Permalink: https://whatsnew.fyi/product/openssl/releases/openssl-4.0.1

- **security** — Fixed heap use-after-free in PKCS7_verify()
- **security** — Fixed CMS AuthEnvelopedData processing that may accept forged messages
- **security** — Fixed unbounded memory growth in the QUIC PATH_CHALLENGE handler
- **security** — Fixed double-free when checking OCSP stapled response
- **security** — Fixed NULL pointer dereference in QUIC server initial packet handling
- **security** — Fixed AES-OCB IV ignored on EVP_Cipher() path
- **security** — Fixed possible heap buffer overflow in ASN.1 multibyte string conversion
- **security** — Fixed out-of-bounds read in CMS password-based decryption
- **security** — Fixed heap buffer over-read in ASN.1 content parsing
- **security** — Fixed PKCS#12 files with PBMAC1 accepted with short HMAC keys
- **security** — Fixed NULL dereference in certificate verification with OCSP checking
- **security** — Fixed possible NULL dereference in password-based CMS decryption
- **security** — Fixed NULL pointer dereference in CRMF EncryptedValue decryption
- **security** — Fixed multi-RecipientInfo Bleichenbacher Oracle in CMS_decrypt() and PKCS7_decrypt()
- **security** — Fixed trust anchor substitution via cert/issuer typo in CMP rootCaKeyUpdate
- **security** — Fixed FFC-DH peer validation using attacker-supplied q
- **security** — Fixed possible out of bounds read in X509_VERIFY_PARAM_set1_email()
- **security** — Fixed incorrect tag processing for empty messages in AES-GCM-SIV and AES-SIV modes
- **fixed** — Fixed regression that led to openssl pkey command crash when encrypting a private key with interactively provided password
- **fixed** — Fixed regression that led to openssl s_client -adv prematurely terminating when reading 16384 bytes in one read() call

OpenSSL 4.0.1 is a security patch release.  The most severe CVE fixed
in this release is High.

This release incorporates the following bug fixes and mitigations:

  * Fixed heap use-after-free in `PKCS7_verify()`.
    ([CVE-2026-45447])

  * Fixed CMS `AuthEnvelopedData` processing may accept forged messages.
    ([CVE-2026-34182])

  * Fixed unbounded memory growth in the QUIC `PATH_CHALLENGE` handler.
    ([CVE-2026-34183])

  * Fixed double-free when checking OCSP stapled response.
    ([CVE-2026-35188])

  * Fixed NULL pointer dereference in QUIC server initial packet handling.
    ([CVE-2026-42764])

  * Fixed AES-OCB IV ignored on `EVP_Cipher()` path.
    ([CVE-2026-45445])

  * Fixed possible heap buffer overflow in ASN.1 multibyte string conversion.
    ([CVE-2026-7383])

  * Fixed out-of-bounds read in CMS password-based decryption.
    ([CVE-2026-9076])

  * Fixed heap buffer over-read in ASN.1 content parsing.
    ([CVE-2026-34180])

  * Fixed PKCS#12 files with PBMAC1 are accepted with short HMAC keys.
    ([CVE-2026-34181])

  * Fixed NULL dereference in certificate verification with OCSP Checking.
    ([CVE-2026-42765])

  * Fixed possible NULL dereference in password-dased CMS decryption.
    ([CVE-2026-42766])

  * Fixed NULL pointer dereference in CRMF `EncryptedValue` decryption.
    ([CVE-2026-42767])

  * Fixed multi-`RecipientInfo` Bleichenbacher Oracle in `CMS_decrypt()`
    and `PKCS7_decrypt()`.
    ([CVE-2026-42768])

  * Fixed trust anchor substitution via `cert`/`issuer` typo in CMP
    `rootCaKeyUpdate`.
    ([CVE-2026-42769])

  * Fixed FFC-DH peer validation uses attacker-supplied `q`.
    ([CVE-2026-42770])

  * Fixed possible out of bounds read in `X509_VERIFY_PARAM_set1_email()`.
    ([CVE-2026-42771])

  * Fixed incorrect tag processing for empty messages in AES-GCM-SIV
    and AES-SIV modes.
    ([CVE-2026-45446])

  * Fixed a regression introduced in 4.0.0 that led to a `openssl pkey`
    command crash when it was invoked to encrypt a private key with password
    being provided interactively.

  * Fixed a regression introduced in 4.0.0 that led to `openssl s_client -adv`
    command prematurely terminating a session when reading input of 16384 bytes
    in one `read()` call.

[CVE-2026-45447]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-45447
[CVE-2026-34182]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-34182
[CVE-2026-34183]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-34183
[CVE-2026-35188]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-35188
[CVE-2026-42764]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-42764
[CVE-2026-45445]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-45445
[CVE-2026-7383]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-7383
[CVE-2026-9076]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-9076
[CVE-2026-34180]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-34180
[CVE-2026-34181]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-34181
[CVE-2026-42765]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-42765
[CVE-2026-42766]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-42766
[CVE-2026-42767]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-42767
[CVE-2026-42768]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-42768
[CVE-2026-42769]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-42769
[CVE-2026-42770]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-42770
[CVE-2026-42771]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-42771
[CVE-2026-45446]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-45446

### openssl-4.0.0 — OpenSSL 4.0.0

- Date: 2026-04-14
- Version: openssl-4.0.0
- Original notes: https://github.com/openssl/openssl/releases/tag/openssl-4.0.0
- Permalink: https://whatsnew.fyi/product/openssl/releases/openssl-4.0.0

- **removed** — Remove extra leading '00:' when printing key data such as an RSA modulus in hexadecimal format where the first byte is >= 0x80
- **changed** — Standardize the width of hexadecimal dumps to 24 bytes for signatures and 16 bytes for everything else
- **changed** — Enforce lower bounds checks when using PKCS5_PBKDF2_HMAC API with FIPS provider
- **added** — Add AKID verification checks when X509_V_FLAG_X509_STRICT is set
- **changed** — Augment CRL verification process with several additional checks
- **changed** — Stop libcrypto from cleaning up globally allocated data via atexit()
- **changed** — Use snprintf() provided by libc in BIO_snprintf() instead of internal implementation
- **changed** — Run OPENSSL_cleanup() in a global destructor, or not at all by default
- **changed** — Make ASN1_STRING opaque
- **changed** — Add const qualifiers to signatures of numerous API functions including those related to X509 processing
- **deprecated** — Deprecate X509_cmp_time(), X509_cmp_current_time(), and X509_cmp_timeframe() in favor of X509_check_certificate_times()
- **removed** — Remove support for the SSLv2 Client Hello
- **removed** — Remove support for SSLv3
- **removed** — Remove support for engines
- **changed** — Disable support of deprecated elliptic curves in TLS according to RFC 8422 at compile-time by default
- **changed** — Disable support of explicit EC curves at compile-time by default
- **removed** — Remove c_rehash script tool in favor of openssl rehash
- **removed** — Remove the deprecated msie-hack option from the openssl ca command
- **removed** — Remove BIO_f_reliable() implementation

OpenSSL 4.0.0 is a feature release adding significant new functionality
to OpenSSL.

This release incorporates the following potentially significant or incompatible
changes:

  * Removed extra leading '00:' when printing key data such as an RSA modulus
    in hexadecimal format where the first (most significant) byte is >= 0x80.

  * Standardized the width of hexadecimal dumps to 24 bytes for signatures
    (to stay within the 80 characters limit) and 16 bytes for everything else.

  * Lower bounds checks are now enforced when using `PKCS5_PBKDF2_HMAC` API
    with FIPS provider.

  * Added AKID verification checks when `X509_V_FLAG_X509_STRICT` is set.

  * Augmented CRL verification process with several additional checks.

  * `libcrypto` no longer cleans up globally allocated data via `atexit()`.

  * `BIO_snprintf()` now uses `snprintf()` provided by libc instead of internal
    implementation.

  * `OPENSSL_cleanup()` now runs in a global destructor, or not at all
    by default.

  * `ASN1_STRING` has been made opaque.

  * Signatures of numerous API functions, including those that are related
    to X509 processing, are changed to include `const` qualifiers for argument
    and return types, where suitable.

  * Deprecated `X509_cmp_time()`, `X509_cmp_current_time()`,
    and `X509_cmp_timeframe()` in favor of `X509_check_certificate_times()`.

  * Removed support for the SSLv2 Client Hello.

  * Removed support for SSLv3.  SSLv3 has been deprecated since 2015,
    and OpenSSL had it disabled by default since version 1.1.0 (2016).

  * Removed support for engines.  The `no-engine` build option
    and the `OPENSSL_NO_ENGINE` macro are always present.

  * Support of deprecated elliptic curves in TLS according to [RFC 8422] was
    disabled at compile-time by default. To enable it, use the
    `enable-tls-deprecated-ec` configuration option.

  * Support of explicit EC curves was disabled at compile-time by default.
    To enable it, use the `enable-ec_explicit_curves` configuration option.

  * Removed `c_rehash` script tool.  Use `openssl rehash` instead.

  * Removed the deprecated `msie-hack` option from the `openssl ca` command.

  * Removed `BIO_f_reliable()` implementation without replacement.
    It was broken since 3.0 release without any complaints.

  * Removed deprecated support for custom `EVP_CIPHER`, `EVP_MD`, `EVP_PKEY`,
    and `EVP_PKEY_ASN1` methods.

  * Removed deprecated fixed SSL/TLS version method functions.

  * Removed deprecated functions `ERR_get_state()`, `ERR_remove_state()`
    and `ERR_remove_thread_state()`. The `ERR_STATE` object is now always
    opaque.

  * Dropped `darwin-i386{,-cc}` and `darwin-ppc{,64}{,-cc}` targets
    from Configurations.

This release adds the following new features:

  * Support for Encrypted Client Hello (ECH, [RFC 9849]).
    See `doc/designs/ech-api.md` for details.

  * Support for [RFC 8998], signature algorithm `sm2sig_sm3`, key exchange
    group `curveSM2`, and [tls-hybrid-sm2-mlkem] post-quantum group
    `curveSM2MLKEM768`.

  * cSHAKE function support as per [SP 800-185].

  * "ML-DSA-MU" digest algorithm support.

  * Support for SNMP KDF and SRTP KDF.

  * FIPS self tests can now be deferred and run as needed when installing
    the FIPS module with the `-defer_tests` option of the `openssl fipsinstall`
    command.

  * Support for using either static or dynamic VC runtime linkage
    on Windows.

  * Support for negotiated FFDHE key exchange in TLS 1.2 in accordance
    with [RFC 7919].

[RFC 8422]: https://datatracker.ietf.org/doc/html/rfc8422
[RFC 9849]: https://datatracker.ietf.org/doc/html/rfc9849
[RFC 8998]: https://datatracker.ietf.org/doc/html/rfc8998#name-iana-considerations
[SP 800-185]: https://csrc.nist.gov/pubs/sp/800/185/final
[RFC 7919]: https://datatracker.ietf.org/doc/html/rfc7919

### openssl-3.3.7 — OpenSSL 3.3.7

- Date: 2026-04-07
- Version: openssl-3.3.7
- Original notes: https://github.com/openssl/openssl/releases/tag/openssl-3.3.7
- Permalink: https://whatsnew.fyi/product/openssl/releases/openssl-3.3.7

- **security** — Fixed incorrect failure handling in RSA KEM RSASVE encapsulation
- **security** — Fixed potential use-after-free in DANE client code
- **security** — Fixed NULL pointer dereference when processing a delta CRL
- **security** — Fixed possible NULL dereference when processing CMS KeyAgreeRecipientInfo
- **security** — Fixed possible NULL dereference when processing CMS KeyTransportRecipientInfo
- **security** — Fixed heap buffer overflow in hexadecimal conversion

OpenSSL 3.3.7 is a security patch release. The most severe CVE fixed in this
release is Moderate.

This release incorporates the following bug fixes and mitigations:

  * Fixed incorrect failure handling in RSA KEM RSASVE encapsulation.
    ([CVE-2026-31790])

  * Fixed potential use-after-free in DANE client code.
    ([CVE-2026-28387])

  * Fixed NULL pointer dereference when processing a delta CRL.
    ([CVE-2026-28388])

  * Fixed possible NULL dereference when processing CMS KeyAgreeRecipientInfo.
    ([CVE-2026-28389])

  * Fixed possible NULL dereference when processing CMS
    KeyTransportRecipientInfo.
    ([CVE-2026-28390])

  * Fixed heap buffer overflow in hexadecimal conversion.
    ([CVE-2026-31789])

[CVE-2026-31790]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-31790
[CVE-2026-28387]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-28387
[CVE-2026-28388]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-28388
[CVE-2026-28389]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-28389
[CVE-2026-28390]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-28390
[CVE-2026-31789]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-31789

### openssl-3.4.5 — OpenSSL 3.4.5

- Date: 2026-04-07
- Version: openssl-3.4.5
- Original notes: https://github.com/openssl/openssl/releases/tag/openssl-3.4.5
- Permalink: https://whatsnew.fyi/product/openssl/releases/openssl-3.4.5

- **security** — Fixed incorrect failure handling in RSA KEM RSASVE encapsulation
- **security** — Fixed potential use-after-free in DANE client code
- **security** — Fixed NULL pointer dereference when processing a delta CRL
- **security** — Fixed possible NULL dereference when processing CMS KeyAgreeRecipientInfo
- **security** — Fixed possible NULL dereference when processing CMS KeyTransportRecipientInfo
- **security** — Fixed heap buffer overflow in hexadecimal conversion

OpenSSL 3.4.5 is a security patch release. The most severe CVE fixed in this
release is Moderate.

This release incorporates the following bug fixes and mitigations:

  * Fixed incorrect failure handling in RSA KEM RSASVE encapsulation.
    ([CVE-2026-31790])

  * Fixed potential use-after-free in DANE client code.
    ([CVE-2026-28387])

  * Fixed NULL pointer dereference when processing a delta CRL.
    ([CVE-2026-28388])

  * Fixed possible NULL dereference when processing CMS KeyAgreeRecipientInfo.
    ([CVE-2026-28389])

  * Fixed possible NULL dereference when processing CMS
    KeyTransportRecipientInfo.
    ([CVE-2026-28390])

  * Fixed heap buffer overflow in hexadecimal conversion.
    ([CVE-2026-31789])

[CVE-2026-31790]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-31790
[CVE-2026-28387]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-28387
[CVE-2026-28388]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-28388
[CVE-2026-28389]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-28389
[CVE-2026-28390]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-28390
[CVE-2026-31789]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-31789

### openssl-3.5.6 — OpenSSL 3.5.6

- Date: 2026-04-07
- Version: openssl-3.5.6
- Original notes: https://github.com/openssl/openssl/releases/tag/openssl-3.5.6
- Permalink: https://whatsnew.fyi/product/openssl/releases/openssl-3.5.6

- **security** — Fixed incorrect failure handling in RSA KEM RSASVE encapsulation
- **security** — Fixed loss of key agreement group tuple structure when the DEFAULT keyword is used in the server-side configuration of the key-agreement group list
- **security** — Fixed potential use-after-free in DANE client code
- **security** — Fixed NULL pointer dereference when processing a delta CRL
- **security** — Fixed possible NULL dereference when processing CMS KeyAgreeRecipientInfo
- **security** — Fixed possible NULL dereference when processing CMS KeyTransportRecipientInfo
- **security** — Fixed heap buffer overflow in hexadecimal conversion

OpenSSL 3.5.6 is a security patch release. The most severe CVE fixed in this
release is Moderate.

This release incorporates the following bug fixes and mitigations:

  * Fixed incorrect failure handling in RSA KEM RSASVE encapsulation.
    ([CVE-2026-31790])

  * Fixed loss of key agreement group tuple structure when the `DEFAULT` keyword
    is used in the server-side configuration of the key-agreement group list.
    ([CVE-2026-2673])

  * Fixed potential use-after-free in DANE client code.
    ([CVE-2026-28387])

  * Fixed NULL pointer dereference when processing a delta CRL.
    ([CVE-2026-28388])

  * Fixed possible NULL dereference when processing CMS KeyAgreeRecipientInfo.
    ([CVE-2026-28389])

  * Fixed possible NULL dereference when processing CMS
    KeyTransportRecipientInfo.
    ([CVE-2026-28390])

  * Fixed heap buffer overflow in hexadecimal conversion.
    ([CVE-2026-31789])

[CVE-2026-31790]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-31790
[CVE-2026-2673]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-2673
[CVE-2026-28387]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-28387
[CVE-2026-28388]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-28388
[CVE-2026-28389]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-28389
[CVE-2026-28390]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-28390
[CVE-2026-31789]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-31789

### openssl-3.6.2 — OpenSSL 3.6.2

- Date: 2026-04-07
- Version: openssl-3.6.2
- Original notes: https://github.com/openssl/openssl/releases/tag/openssl-3.6.2
- Permalink: https://whatsnew.fyi/product/openssl/releases/openssl-3.6.2

- **security** — Fixed incorrect failure handling in RSA KEM RSASVE encapsulation
- **security** — Fixed loss of key agreement group tuple structure when the DEFAULT keyword is used in the server-side configuration of the key-agreement group list
- **security** — Fixed out-of-bounds read in AES-CFB-128 on x86-64 CPUs with AVX-512 support
- **security** — Fixed potential use-after-free in DANE client code
- **security** — Fixed NULL pointer dereference when processing a delta CRL
- **security** — Fixed possible NULL dereference when processing CMS KeyAgreeRecipientInfo
- **security** — Fixed possible NULL dereference when processing CMS KeyTransportRecipientInfo
- **security** — Fixed heap buffer overflow in hexadecimal conversion

OpenSSL 3.6.2 is a security patch release. The most severe CVE fixed in this
release is Moderate.

This release incorporates the following bug fixes and mitigations:

  * Fixed incorrect failure handling in RSA KEM RSASVE encapsulation.
    ([CVE-2026-31790])

  * Fixed loss of key agreement group tuple structure when the `DEFAULT` keyword
    is used in the server-side configuration of the key-agreement group list.
    ([CVE-2026-2673])

  * Fixed out-of-bounds read in AES-CFB-128 on x86-64 CPUs with AVX-512 support.
    ([CVE-2026-28386])

  * Fixed potential use-after-free in DANE client code.
    ([CVE-2026-28387])

  * Fixed NULL pointer dereference when processing a delta CRL.
    ([CVE-2026-28388])

  * Fixed possible NULL dereference when processing CMS KeyAgreeRecipientInfo.
    ([CVE-2026-28389])

  * Fixed possible NULL dereference when processing CMS
    KeyTransportRecipientInfo.
    ([CVE-2026-28390])

  * Fixed heap buffer overflow in hexadecimal conversion.
    ([CVE-2026-31789])

[CVE-2026-31790]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-31790
[CVE-2026-2673]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-2673
[CVE-2026-28386]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-28386
[CVE-2026-28387]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-28387
[CVE-2026-28388]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-28388
[CVE-2026-28389]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-28389
[CVE-2026-28390]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-28390
[CVE-2026-31789]: https://openssl-library.org/news/vulnerabilities/#CVE-2026-31789