GitHub Advisoryadvisory · PyPI

GHSA-jm82-fx9c-mx94 pypdf: Missing stream length values ignore defined limits

MEDIUM Published 2026-06-18 Modified 2026-06-18 Official page ↗
Ecosystem
PyPI
Packages
pypdf
Severity
Moderate
CVSS vector
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
Weaknesses
CWE-400, CWE-770
Reviewed
2026-06-18

Affected packages

• PyPI pypdf: < 6.13.3 → fixed in 6.13.3

Description

Impact An attacker who uses this vulnerability can craft a PDF which leads to large memory usage, as `MAX_DECLARED_STREAM_LENGTH` is sometimes ignored. This requires parsing a content stream without a `/Length` value. Patches This has been fixed in pypdf==6.13.3. Workarounds If you cannot upgrade yet, consider applying the changes from PR #3871.

Related

Weakness · CWE (2)

  • CWE-400 Uncontrolled Resource Consumption weakness
  • CWE-770 Allocation of Resources Without Limits or Throttling weakness

References