CVE-2026-22691

5.3 MEDIUM
Published: January 10, 2026 Modified: January 22, 2026
View on NVD

Description

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.

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CVSS v3.x Details

0.0 Low Medium High Critical 10.0
Vector String
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

References to Advisories, Solutions, and Tools

Patch Vendor Advisory Exploit Third Party Advisory
https://github.com/py-pdf/pypdf/pull/3594
Source: security-advisories@github.com
Issue Tracking Patch
https://github.com/py-pdf/pypdf/releases/tag/6.6.0
Source: security-advisories@github.com
Release Notes
https://github.com/py-pdf/pypdf/security/advisories/GHSA-4f6g-68pf-7vhv
Source: security-advisories@github.com
Vendor Advisory Mitigation

4 reference(s) from NVD

Quick Stats

CVSS v3 Score
5.3 / 10.0
EPSS (Exploit Probability)
0.0%
5th percentile
Exploitation Status
Not in CISA KEV

Weaknesses (CWE)

Affected Vendors

pypdf_project