GHSA-pg7v-jwj7-p798: pillow (CVE-2026-59203)

Package	Ecosystem	Affected	Fixed in
pillow	PyPI	>=12.0.0, <12.3.0	12.3.0

Machine-written summary

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

Pillow versions 12.0.0 through 12.2.0 are vulnerable to a denial of service in the EPS parser: a crafted EPS file with a negative byte count in a %%BeginBinary directive makes Image.open() loop forever, consuming CPU. An attacker only needs to supply such a file to an application that opens images, such as an upload or validation step. Upgrade to Pillow 12.3.0, which contains the fix.

Written 4 Nov 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
5.3	Medium	3.1	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L	CNA (GitHub_M)

CISA KEV Not listed.
EPSS 0.0040, the 34th percentile, on 15 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

Timeline

7 Jul 2026, 08:57 UTC Published by the maintainers as a GitHub repository advisory
31 Oct 2026, 14:29 UTC First seen by agentprime
31 Oct 2026, 14:29 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.