python-pillow/pillow · Security
Pillow: Quadratic GIF comment copying during save
- GHSA ID
- GHSA-fc9g-5qg7-mf45
- CVE ID
- CVE-2026-112891
- Severity
- medium
- Published
- Updated
- CVSS v4
- 6.9 · 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
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.
CWEs
- CWE-407 · Inefficient Algorithmic Complexity
References
- 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/releases/tag/13.0.0 ↗
- https://github.com/advisories/GHSA-fc9g-5qg7-mf45 ↗