pypdf is a free and open-source pure-python PDF library. Prior to 6.12.0, an attacker who uses this vulnerability can craft a PDF which leads to long runtimes. This requires cross-reference streams with /W [0 0 0] values and large /Size values. This vulnerability is fixed in 6.12.0.
Fix
Patch, vendor advisory and mitigation references on NVD 2
- https://github.com/py-pdf/pypdf/pull/3791 Issue Tracking, Patch
- https://github.com/py-pdf/pypdf/security/advisories/GHSA-248m-82v9-q6g6 Patch, Vendor Advisory
Every line above is quoted from NVD, CISA, Microsoft, the vendor's own advisory or DISA; nothing is generated.
Change history 1
- First seenCVSS 5.1 · pypdf_projectNVD modified 2026-10-14 20:10
Affected (CPE criteria) 1
cpe:2.3:a:pypdf_project:pypdf:*:*:*:*:*:*:*:*
References 3
- https://github.com/py-pdf/pypdf/pull/3791 Issue Tracking, Patch
- https://github.com/py-pdf/pypdf/releases/tag/6.12.0 Release Notes
- https://github.com/py-pdf/pypdf/security/advisories/GHSA-248m-82v9-q6g6 Patch, Vendor Advisory