Vulnerability · Published Oct 19, 2026 · Assigned by GitHub_M
CVE-2026-112401Pillow: Quadratic GIF comment concatenation allows DoS in Image.open()
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 0.6% (higher than 51% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
Pillow is a Python imaging library. From 5.4.0 until 13.0.0, Pillow performs quadratic copying while parsing GIF comments. GifImageFile._seek() repeatedly appends immutable bytes for comment sub-blocks and multiple comment extensions, and frame zero is parsed during Image.open(). An attacker can submit a small-dimension GIF containing many comment extensions to any application that opens the file. This can consume excessive CPU and deny service before the application can inspect the image. 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-2026-112401 |
| Debian:13 | pillow | no fix listed | DEBIAN-CVE-2026-112401 |
| Debian:14 | pillow | no fix listed | DEBIAN-CVE-2026-112401 |
| PyPI | pillow | 13.0.0 | GHSA-74r2-7ff9-mjj2 |
| Ubuntu:22.04:LTS | pillow | no fix listed | UBUNTU-CVE-2026-112401 |
| Ubuntu:24.04:LTS | pillow | no fix listed | UBUNTU-CVE-2026-112401 |
| Ubuntu:26.04:LTS | pillow | no fix listed | UBUNTU-CVE-2026-112401 |
| Ubuntu:26.10 | pillow | no fix listed | UBUNTU-CVE-2026-112401 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| python-pillow | Pillow | >= 5.4.0, < 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