CVE-2026-59937

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

CVSS 6.9 MEDIUMCWE-400

Vexday Risk Score

10Low

SSVC decision (CISA)

Track

No exploitation signal → monitor

CVSS 6.9EPSS —KEV nãoPoC —Nuclei —Metasploit —Patch —

Lifecycle

08 Jul 2026Published on NVD

Recommendation: Monitor — no exploitation signal at the moment.

pypdf is a free and open-source pure-python PDF library. Prior to 6.14.0, an attacker can craft a PDF with repeated malformed cross-reference streams that cause pypdf to spend long runtimes recovering broken cross-reference table entries. This issue is fixed in version 6.14.0.

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N

Affected products

py-pdf · pypdf

References

https://github.com/py-pdf/pypdf/commit/b5fc5aa714f4b696fb9b1deaa35a9e4a4eb50dae https://github.com/py-pdf/pypdf/pull/3887 https://github.com/py-pdf/pypdf/releases/tag/6.14.0 https://github.com/py-pdf/pypdf/security/advisories/GHSA-55h5-xmcq-c37v