Vulnerability · Published Oct 19, 2026 · Assigned by GitHub_M
CVE-2026-112891Pillow: Quadratic GIF comment copying during save
Medium 6.9
In plain English
A medium-severity security flaw in Pillow from python-pillow. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 46% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
Pillow is a Python imaging library. From 9.2.0 until 13.0.0, Pillow performs quadratic copying when saving a GIF with a long comment. _get_global_header() repeatedly copies portions of comment data while assembling the global header, including comments retained from an untrusted input image. An attacker can supply an image with a large GIF comment to an application that saves it as GIF. This can consume excessive CPU and delay or deny service. This issue is fixed in version 13.0.0.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | pillow | no fix listed | DEBIAN-CVE-2026-112891 |
| Debian:13 | pillow | no fix listed | DEBIAN-CVE-2026-112891 |
| Debian:14 | pillow | no fix listed | DEBIAN-CVE-2026-112891 |
| PyPI | pillow | 13.0.0 | GHSA-fc9g-5qg7-mf45 |
| Ubuntu:24.04:LTS | pillow | no fix listed | UBUNTU-CVE-2026-112891 |
| Ubuntu:26.04:LTS | pillow | no fix listed | UBUNTU-CVE-2026-112891 |
| Ubuntu:26.10 | pillow | no fix listed | UBUNTU-CVE-2026-112891 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| python-pillow | Pillow | >= 9.2.0, < 13.0.0 |
Weakness: CWE-407 · 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