CVE-2026-22691: pypdf has possible long runtimes for malformed startxref
(updated )
An attacker who exploits this vulnerability can craft a PDF which leads to possibly long runtimes for invalid startxref entries. When rebuilding the cross-reference table, PDF files with lots of whitespace characters become problematic. Only the non-strict reading mode is affected.
References
- github.com/advisories/GHSA-4f6g-68pf-7vhv
- github.com/py-pdf/pypdf
- github.com/py-pdf/pypdf/commit/294165726b646bb7799be1cc787f593f2fdbcf45
- github.com/py-pdf/pypdf/pull/3594
- github.com/py-pdf/pypdf/releases/tag/6.6.0
- github.com/py-pdf/pypdf/security/advisories/GHSA-4f6g-68pf-7vhv
- nvd.nist.gov/vuln/detail/CVE-2026-22691
Code Behaviors & Features
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