GitHub Advisoryadvisory · PyPI
GHSA-fc9g-5qg7-mf45 Pillow: Quadratic GIF comment copying during save
MEDIUM
Official page ↗
- Aliases
- CVE-2026-112891
- Ecosystem
- PyPI
- Packages
- pillow
- Severity
- Moderate
- CVSS vector
- CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
- Weaknesses
- CWE-407
- Reviewed
- 2026-10-21
Affected packages
• PyPI pillow: >= 9.2.0, < 13.0.0 → fixed in 13.0.0
Description
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.
Related
Alias · CVE (1)
- CVE-2026-112891 Pillow is a Python imaging library. vulnerability
Weakness · CWE (1)
- CWE-407 Inefficient Algorithmic Complexity weakness
References
- https://github.com/python-pillow/Pillow/security/advisories/GHSA-fc9g-5qg7-mf45 web
- https://nvd.nist.gov/vuln/detail/CVE-2026-112891 advisory
- https://github.com/python-pillow/Pillow/commit/68a3fe957d8a4d552e8c69d96066d749f0614c7e web
- https://github.com/python-pillow/Pillow package
- https://github.com/python-pillow/Pillow/releases/tag/13.0.0 web