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Advisory record · GHSA-9mx8-4j7g-633p

pypdf: Possible infinite loop when removing tree items

CVSS 6.0 MediumEPSS 0.0035 · 29th percentile

Published by the GitHub Advisory Database at 21 Oct 2026, 16:55 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

PackageEcosystemAffectedFixed in
pypdfPyPI<6.20.16.20.1
Identifiers
GHSA-9mx8-4j7g-633p · CVE-2026-113793
Weakness (CWE)
CWE-835
Tags
Published
21 Oct 2026
Updated
21 Oct 2026

Machine-written summary

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

pypdf versions before 6.20.1 can enter an infinite loop when a crafted PDF is processed in a way that removes an object from a tree, such as an outline item. An attacker who can supply the PDF to be processed can cause the process to hang, which is a denial of service. Upgrade to pypdf 6.20.1 or later. The source gives no other workaround that a user can apply themselves.

Written 1 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

ScoreRatingCVSSVectorSource
6.0 Medium 4.0 CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N CNA (GitHub_M)
  • CISA KEV Not listed.
  • EPSS 0.0035, the 29th percentile, on 7 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

Timeline

  1. 21 Oct 2026, 16:17 UTC Confirmed by NVD
  2. 31 Oct 2026, 14:08 UTC First seen by agentprime
  3. 31 Oct 2026, 14:08 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.