CVE-2026-112399

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.

CVSS 4.0

8.7CVSS: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

0.4% chance of exploitation in the next 30 days; higher than 32% of CVEs (scores of 2026-10-25)

CWE

CWE-789

Published

2026-10-19

Modified

2026-10-20

Record from

the NVD, synced 2026-10-21

Packages (OSV)

References

• https://github.com/python-pillow/Pillow/commit/f1acfc54c53502948d0d14121872061df931db48
• https://github.com/python-pillow/Pillow/releases/tag/13.0.0
• https://github.com/python-pillow/Pillow/security/advisories/GHSA-5xm2-6676-qcp9

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