# openzeppelin-contracts v5.5.0

- Product: openzeppelin-contracts (https://whatsnew.fyi/product/openzeppelin-contracts)
- Vendor: OpenZeppelin
- Date: 2025-10-31
- Version: v5.5.0
- Original notes: https://github.com/OpenZeppelin/openzeppelin-contracts/releases/tag/v5.5.0
- Permalink: https://whatsnew.fyi/product/openzeppelin-contracts/releases/v5.5.0

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.

Reuse: the summaries, labels and curation here are © What's New. Quote freely with attribution and a link back; wholesale republication of the corpus is not permitted — terms: https://whatsnew.fyi/terms. The vendors' own release notes remain their publishers'.

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- **fixed** — AccountERC7579: Prevent revert in isModuleInstalled for fallback modules when additionalContext has fewer than 4 bytes, returning false instead to ensure ERC-7579 compliance
- **fixed** — ERC165Checker: Ensure supportsERC165 function returns false if the target reverts during the supportsInterface(0xffffffff) call
- **changed** — Account: Add signature argument to the internal _validateUserOp function for custom signature handling logic
- **changed** — AccountERC7579: Installing and uninstalling fallback modules now require initData and deInitData arguments to be at least 4 bytes long and reverts with ERC7579CannotDecodeFallbackData instead of treating missing bytes as 0x00
- **changed** — ERC6909 and its extensions are no longer marked as draft since EIP-6909 is now final, requiring updated import paths
- **removed** — SignerERC7702 is renamed to SignerEIP7702, requiring updated imports and inheritance
- **removed** — ERC721Holder, ERC1155Holder, ReentrancyGuard and ReentrancyGuardTransient are flagged as stateless and are no longer transpiled
- **changed** — Update minimum pragma to 0.8.24 in AccessControlEnumerable, Arrays, CircularBuffer, EIP712, EnumerableMap, EnumerableSet, ERC1155, ERC1155Burnable, ERC1155Pausable, ERC1155Supply, ERC1155URIStorage, ERC20Votes, ERC4626, ERC721Burnable, ERC721Consecutive, ERC721Enumerable, ERC721Pausable, ERC721Royalty, ERC721URIStorage, ERC721Votes, ERC721Wrapper, ERC7739, Heap, MerkleTree, MessageHashUtils, Strings, Votes and VotesExtended
- **deprecated** — Initializable and UUPSUpgradeable are no longer transpiled; an alias is present in the @openzeppelin/contracts-upgradeable package that will be removed in the next major release
- **deprecated** — ECDSA signature malleability protection is partly deprecated
- **changed** — ERC4626: Compute maxWithdraw using maxRedeem and previewRedeem so that changes to the preview functions affect the max functions
- **added** — InteroperableAddress: Add a library for formatting and parsing ERC-7930 interoperable addresses
- **added** — ERC7786Recipient: Generic ERC-7786 cross-chain message recipient contract
- **added** — IERC7786: Add the interface for ERC-7786 Cross-Chain Messaging Gateway
- **added** — SignerWebAuthn: Add an abstract signer that verifies WebAuthn signatures with a P256 fallback
- **added** — Add constructors to the different signers
- **added** — ERC7913WebAuthnVerifier: Add an ERC-7913 verifier that verifies WebAuthn Authentication Assertions for P256 identities
- **added** — WebAuthn: Add a library for verifying WebAuthn Authentication Assertions
- **added** — ECDSA: Add parse and parseCalldata to parse bytes signatures of length 65 or 64 into v, r, s components
- **added** — ECDSA: Add recoverCalldata and tryRecoverCalldata, variants of recover and tryRecover that are more efficient when signatures are in calldata
- **added** — SignatureChecker: Add isValidSignatureNowCalldata for efficient processing of calldata signatures

###### Bug fixes

- `AccountERC7579`: Prevent revert in `isModuleInstalled` for fallback modules when `additionalContext` has fewer than 4 bytes. The function now returns `false` instead of reverting, ensuring ERC-7579 compliance. ([#5961](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/5961))
- `ERC165Checker`: Ensure the `supportsERC165` function returns false if the target reverts during the `supportsInterface(0xffffffff)` call. ([#5810](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/5880))

###### Breaking changes

- `Account`: Add `signature` argument to the internal `_validateUserOp` function for custom signature handling logic. Developers overriding it must now provide the signature from the user operation (i.e. `userOp.signature`) to keep compatibility. ([#5976](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/5976))
- `AccountERC7579`: Installing and uninstalling fallback modules now require the corresponding `initData` and `deInitData` arguments to be at least 4 bytes long (matching the selector to which the fallback module is registered). It now reverts with `ERC7579CannotDecodeFallbackData` instead of treating the missing bytes as `0x00`. ([#5974](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/5974))
- `ERC6909` and its extensions (`ERC6909ContentURI`, `ERC6909Metadata` and `ERC6909TokenSupply`) are no longer marked as draft since [EIP-6909](https://eips.ethereum.org/EIPS/eip-6909) is now final. Developers must update the import paths. Contracts behavior is not modified. ([#5929](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/5929))
- `SignerERC7702` is renamed as `SignerEIP7702`. Imports and inheritance must be updated to that new name and path. Behavior is unmodified. ([#5932](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/5932))
- `ERC721Holder`, `ERC1155Holder`, `ReentrancyGuard` and `ReentrancyGuardTransient` are flagged as stateless and are no longer transpiled. Developers using their upgradeable variants from `@openzeppelin/contracts-upgradeable` must update their imports to use the equivalent version available in `@openzeppelin/contracts`. ([#5944](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/5944), [#5942](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/5942))
- Update minimum pragma to 0.8.24 in `AccessControlEnumerable`, `Arrays`, `CircularBuffer`, `EIP712`, `EnumerableMap`, `EnumerableSet`, `ERC1155`, `ERC1155Burnable`, `ERC1155Pausable`, `ERC1155Supply`, `ERC1155URIStorage`, `ERC20Votes`, `ERC4626`,`ERC721Burnable`, `ERC721Consecutive`, `ERC721Enumerable`, `ERC721Pausable`, `ERC721Royalty`, `ERC721URIStorage`, `ERC721Votes`, `ERC721Wrapper`, `ERC7739`, `Heap`, `MerkleTree`, `MessageHashUtils`, `Strings`, `Votes` and `VotesExtended`. ([#5723](https://github.com/OpenZeppelin/openzeppelin-contracts/issues/5723), [#5726](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/5726), [#5965](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/5965))

###### Deprecation

- `Initializable` and `UUPSUpgradeable` are no longer transpiled. An alias is present in the `@openzeppelin/contracts-upgradeable` package that redirect to the corresponding file in `@openzeppelin/contracts`. These alias will be removed in the next major release. Developers are advised to update their imports to get these files directly from the `@openzeppelin/contracts` package. [#5941](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/5941)
- `ECDSA` signature malleability protection is partly deprecated. See documentation for more details. [#5814](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/5814)

###### Changes by category

###### Tokens

- `ERC4626`: compute `maxWithdraw` using `maxRedeem` and `previewRedeem` so that changes to the preview functions affect the max functions. ([#5130](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/5130))

###### Cross-chain

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