CVE-2026-22691

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 v3 5.3 MEDIUM

5.3^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 3.9 / Impact : 1.4

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact LOW

Scope UNCHANGED

References

Link	Resource
https://github.com/py-pdf/pypdf/commit/294165726b646bb7799be1cc787f593f2fdbcf45	Patch
https://github.com/py-pdf/pypdf/pull/3594	Issue Tracking Patch
https://github.com/py-pdf/pypdf/releases/tag/6.6.0	Release Notes
https://github.com/py-pdf/pypdf/security/advisories/GHSA-4f6g-68pf-7vhv	Vendor Advisory Mitigation

Configurations

Configuration 1 (hide)

cpe:2.3:a:pypdf_project:pypdf:*:*:*:*:*:*:*:*

History

No history.

Information

Published : 2026-01-10 05:16

Updated : 2026-01-22 15:01

NVD link : CVE-2026-22691

Mitre link : CVE-2026-22691

CVE.ORG link : CVE-2026-22691

JSON object : View

Products Affected

pypdf_project

pypdf

CWE

CWE-400

Uncontrolled Resource Consumption

CWE-1333

Inefficient Regular Expression Complexity

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