# Fastfetch 2.66.1

- Product: Fastfetch (https://whatsnew.fyi/product/fastfetch)
- Vendor: fastfetch-cli
- Date: 2026-09-01
- Version: 2.66.1
- Original notes: https://github.com/fastfetch-cli/fastfetch/releases/tag/2.66.1
- Permalink: https://whatsnew.fyi/product/fastfetch/releases/2.66.1

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.

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- **fixed** — Fixed I/O rate calculation precision and prevented division by zero in DiskIO and NetIO
- **fixed** — Fixed ash and fish version detection, including a potential out-of-bounds read in Shell
- **fixed** — Fixed integer handling for varying sysctl data lengths in Sysctl
- **fixed** — Fixed several memory leaks in Camera, Codec, Display, Separator and Weather
- **fixed** — Fixed Base64 encoding on big-endian hosts
- **fixed** — Fixed VP9 codec detection and macOS 10.15 Codec compatibility
- **fixed** — Relaxed accepted HTTP response formats and fixed invalid PublicIP URL parsing in Networking and PublicIP
- **added** — Added a response size limit to prevent excessive network memory allocation in Networking
- **added** — Added integer overflow checks to string buffer capacity handling in FFstrbuf
- **fixed** — Fixed Ubuntu Studio Core detection in OS for Linux
- **fixed** — Fixed preferred monitor mode detection for KDE Plasma in Display for Linux
- **fixed** — Fixed bright colors being enabled incorrectly in light themes in Display
- **fixed** — Fixed a macOS compiler warning in Version

> [!WARNING]
> This is a bugfix-only release that targets v2.66 (the last release before fastfetch moved to C23).
> This is for distros that use old compilers which have no C23 support.
> No binaries are provided. Normal users should not use this version.

Bugfixes:
* Fixed I/O rate calculation precision and prevented division by zero. (DiskIO / NetIO)
* Fixed ash and fish version detection, including a potential out-of-bounds read. (Shell)
* Fixed integer handling for varying sysctl data lengths. (Sysctl)
* Fixed several memory leaks in Camera, Codec, Display, Separator and Weather.
* Fixed Base64 encoding on big-endian hosts. (Base64)
* Fixed VP9 codec detection and macOS 10.15 Codec compatibility. (Codec, macOS)
* Relaxed accepted HTTP response formats and fixed invalid PublicIP URL parsing. (Networking / PublicIP)
* Added a response size limit to prevent excessive network memory allocation. (Networking)
* Added integer overflow checks to string buffer capacity handling. (FFstrbuf)
* Fixed Ubuntu Studio Core detection. (OS, Linux)
* Fixed preferred monitor mode detection for KDE Plasma. (Display, Linux)
* Fixed bright colors being enabled incorrectly in light themes. (Display)
* Fixed a macOS compiler warning. (Version, macOS)