GHSA-fc9g-5qg7-mf45
Pillow: Quadratic GIF comment copying during save
Packages
Details
As written in the advisory (Markdown source, shown as plain text).
On Pillow 12.3.0 and upstream `main` (`ad277e2761b489681e71b51e91367d46b0ceabb9`), a GIF with a long comment makes `_get_global_header()` copy portions of the comment repeatedly when saving, including comments carried over from untrusted images. I suggest provisional **Moderate** severity for crafted-image CPU denial of service, with CVSS-B 6.9 assuming a network service automatically opens unauthenticated uploads and they are resaved as GIFs; impact depends on input-size, concurrency, and worker CPU limits.
References
External links from the advisory. They lead to third-party sites.
- https://github.com/python-pillow/Pillow/security/advisories/GHSA-fc9g-5qg7-mf45
- https://nvd.nist.gov/vuln/detail/CVE-2026-112891
- https://github.com/python-pillow/Pillow/commit/68a3fe957d8a4d552e8c69d96066d749f0614c7e
- https://github.com/python-pillow/Pillow
- https://github.com/python-pillow/Pillow/releases/tag/13.0.0