CVE-2026-54651: pypdf: Possible infinite loop when processing threads/articles in writer

July 9, 2026

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.

References

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

Code Behaviors & Features

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