Vulnerability · Published Oct 19, 2026 · Assigned by GitHub_M
CVE-2026-112901Pillow: ReDoS in XbmImagePlugin: 512-byte file stalls Image.open() for minutes
Medium 6.9
In plain English
A medium-severity regular-expression denial of service 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 45% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
Pillow is a Python imaging library. Prior to 13.0.0, Pillow's XBM header parser is vulnerable to regular-expression denial of service. In XbmImageFile._open, when an application calls Image.open() on a small crafted XBM file, XbmImagePlugin applies a backtracking expression to the attacker-controlled header before image dimensions are accepted, stalling a worker for minutes and denying 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-2026-112901 |
| Debian:13 | pillow | no fix listed | DEBIAN-CVE-2026-112901 |
| Debian:14 | pillow | no fix listed | DEBIAN-CVE-2026-112901 |
| PyPI | pillow | 13.0.0 | GHSA-xgh8-jp6q-p5x8 |
| PyPI | pillow | 13.0.0 | PYSEC-2026-4335 |
| Ubuntu:22.04:LTS | pillow | no fix listed | UBUNTU-CVE-2026-112901 |
| Ubuntu:24.04:LTS | pillow | no fix listed | UBUNTU-CVE-2026-112901 |
| Ubuntu:26.04:LTS | pillow | no fix listed | UBUNTU-CVE-2026-112901 |
| Ubuntu:26.10 | pillow | no fix listed | UBUNTU-CVE-2026-112901 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| python-pillow | Pillow | < 13.0.0 |
Weakness: CWE-1333 · 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