Connect your agent
AdvisoriesCriticalCheck your lockfilePluginHow it worksPricing Connect your agent

Advisory record · GHSA-f2g6-542v-9j58

Pillow: Infinite loop in PdfParser.rewrite_pages on page tree Parent cycle

CVSS 8.7 HighEPSS 0.0057 · 47th percentile

Published by the GitHub Advisory Database at 21 Oct 2026, 21:21 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

PackageEcosystemAffectedFixed in
pillowPyPI>=5.1.0, <13.0.013.0.0
Identifiers
GHSA-f2g6-542v-9j58 · BIT-pillow-2026-112406 · CVE-2026-112406
Weakness (CWE)
CWE-835
Tags
Published
21 Oct 2026
Updated
26 Oct 2026

Machine-written summary

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

Pillow versions from 5.1.0 before 13.0.0 can hang forever when appending an image to an existing PDF with a cyclic /Parent chain in its page tree. An attacker who supplies such a PDF to an application saving with append=True can pin a worker at 100% CPU, a denial of service that only an external timeout stops. Upgrade to Pillow 13.0.0, which fixes the issue.

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

ScoreRatingCVSSVectorSource
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 0.0057, the 47th percentile, on 5 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

Timeline

  1. 31 Oct 2026, 14:07 UTC First seen by agentprime
  2. 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.