CVE-2026-112399CWE-789

CVE-2026-112399

published October 20, 2026

CVSS
8.7
EPSS
0%
Percentile
20.6
In the wild
Unconfirmed
What it is

Pillow is a Python imaging library. From 8.1.0 until 13.0.0, Pillow can allocate an APNG disposal background at the full canvas size before applying the decompression-bomb check. A crafted APNG with a small first frame, a very large declared canvas, and background disposal or first-frame OP_PREVIOUS reaches PngImageFile._seek while Image.open() positions frame zero. The full-canvas allocation occurs inside Image.open() without requiring pixel loading or frame iteration. This can exhaust memory and deny service. This issue is fixed in version 13.0.0.

The record
Technical detail
CVSS
8.7 · NONE
CVSS v4.0
8.7 · CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
EPSS
0.00291 · 20.6th percentile
Weakness
CWE-789 · Memory Allocation with Excessive Size Value
Published
2026-10-20T02:17Z
References (3)
https://github.com/python-pillow/Pillow/commit/f1acfc54c53502948d0d14121872061df931db48 · [email protected]https://github.com/python-pillow/Pillow/releases/tag/13.0.0 · [email protected]https://github.com/python-pillow/Pillow/security/advisories/GHSA-5xm2-6676-qcp9 · [email protected]
EPSS history
Timeline
  • 21 OCT 03:27Z
    EPSS moved — → 0%
    epss
  • 19 OCT 21:10Z
    Pillow: APNG background disposal allocates full canvas before decompression bomb check
    cvelistv5
  • 19 OCT 21:10Z
    Pillow: APNG background disposal allocates full canvas before decompression bomb check
    cvelistv5