CVE-2026-54651

Summary

pypdf: Possible infinite loop when processing threads/articles in writer

Severity

medium

EPSS

0.2% (p5)

CWE

CWE-835

Also known as

GHSA-g9xf-7f8q-9mcj

Published

2026-07-09

Updated

2026-07-09

Advisory details

Impact

An attacker who uses this vulnerability can craft a PDF which leads to an infinite loop. This requires merging a file with threads/articles into a writer.

Patches

This has been fixed in pypdf==6.13.1.

Workarounds

If users cannot upgrade yet, consider applying the changes from PR #3839.

References

• https://github.com/advisories/GHSA-g9xf-7f8q-9mcj
• https://github.com/py-pdf/pypdf/security/advisories/GHSA-g9xf-7f8q-9mcj
• https://nvd.nist.gov/vuln/detail/CVE-2026-54651
• https://github.com/py-pdf/pypdf/pull/3839
• https://github.com/py-pdf/pypdf/releases/tag/6.13.1

Related advisories

• CVE-2026-59935 — high · PyPI/pypdf
• CVE-2026-59936 — high · PyPI/pypdf
• CVE-2026-84309 — medium · PyPI/pypdf
• CVE-2026-82398 — medium · PyPI/pypdf
• CVE-2026-84310 — medium · PyPI/pypdf
• CVE-2026-84311 — medium · PyPI/pypdf
• CVE-2026-71870 — medium · PyPI/pypdf
• CVE-2026-71852 — medium · PyPI/pypdf

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