GitHub Advisoryadvisory · PyPI

GHSA-jr96-gvgh-j3r4 pypdf: Possible long runtimes for repeated malformed cross-reference entries (Follow-up)

HIGH Published 2026-10-23 Modified 2026-10-23 Official page ↗
Aliases
CVE-2026-115585
Ecosystem
PyPI
Packages
pypdf
Severity
High
CVSS vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
Weaknesses
CWE-400, CWE-407
Reviewed
2026-10-23

Affected packages

• PyPI pypdf: < 6.21.2 → fixed in 6.21.2

Description

Impact An attacker who uses this vulnerability can craft a PDF which leads to long runtimes. This requires cross-reference streams with repeated malformed cross-reference streams. Patches This has been fixed in pypdf==6.21.2. Workarounds If you cannot upgrade yet, consider applying the changes from PR #4240. Notes This is a follow-up to https://github.com/py-pdf/pypdf/security/advisories/GHSA-55h5-xmcq-c37v, which had the side-effect of still loading the whole stream again despite the cache being present.

Related

Alias · CVE (1)

  • CVE-2026-115585 pypdf is a free and open-source pure-python PDF library. vulnerability

Weakness · CWE (2)

  • CWE-400 Uncontrolled Resource Consumption weakness
  • CWE-407 Inefficient Algorithmic Complexity weakness

References