CVE-2026-59937: pypdf: Possible long runtimes for repeated malformed cross-reference entries

July 23, 2026

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.

References

github.com/advisories/GHSA-55h5-xmcq-c37v
github.com/py-pdf/pypdf/commit/b5fc5aa714f4b696fb9b1deaa35a9e4a4eb50dae
github.com/py-pdf/pypdf/pull/3887
github.com/py-pdf/pypdf/releases/tag/6.14.0
github.com/py-pdf/pypdf/security/advisories/GHSA-55h5-xmcq-c37v
nvd.nist.gov/vuln/detail/CVE-2026-59937

Code Behaviors & Features

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