Medium 5.3Published Jan 10, 2026

CVE-2026-22691pypdf is a free and open-source pure-python PDF library.

Updated under an hour ago (2026-10-19 07:23 UTC)

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No exploitation reported and no EPSS estimate yet.

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Every CVE for pypdf_project pypdf

Exploited in the last 30 days

pypdf is a free and open-source pure-python PDF library. Prior to version 6.6.0, pypdf has possible long runtimes for malformed startxref. An attacker who uses 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. Only the non-strict reading mode is affected. This issue has been patched in version 6.6.0.

CVSS: 5.3 MEDIUM (v3.1, NVD)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Weakness (CWE): CWE-400, CWE-1333
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: Not given
NVD analysis: Analyzed
Record last updated: Jun 17, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

pypdf_project pypdf pypdf_project:pypdf	before 6.6.0	NVD

References

https://github.com/py-pdf/pypdf/commit/294165726b646bb7799be1cc787f593f2fdbcf45patch
https://github.com/py-pdf/pypdf/pull/3594issue-tracking, patch
https://github.com/py-pdf/pypdf/releases/tag/6.6.0release-notes
https://github.com/py-pdf/pypdf/security/advisories/GHSA-4f6g-68pf-7vhvmitigation, vendor-advisory

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.