GHSA-5xm2-6676-qcp9: pillow (CVE-2026-112399)

Package	Ecosystem	Affected	Fixed in
pillow	PyPI	>=8.1.0, <13.0.0	13.0.0

Machine-written summary

Summary written by Claude Haiku from the source advisory. Not reviewed by a person.

GHSA-5xm2-6676-qcp9 affects Pillow from 8.1.0 up to, but not including, 13.0.0. When Pillow opens an animated PNG whose first frame requests background disposal, it allocates and fills memory sized by the image's declared width and height before the decompression-bomb check runs. An attacker can supply a roughly 126-byte file, with default settings and no further calls, to cause a multi-gigabyte memory spike per file, which can get the process killed by the operating system. The fix is to upgrade to Pillow 13.0.0 or later.

Written 31 Oct 2026.

Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

Severity and exploitation

Score	Rating	CVSS	Vector	Source
8.7	High	4.0	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	CNA (GitHub_M)

CISA KEV Not listed.
EPSS 0.0053, the 44th percentile, on 5 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

Timeline

31 Oct 2026, 14:07 UTC First seen by agentprime
31 Oct 2026, 14:07 UTC Confirmed by OSV

Sources

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.