pypdf has possible long runtimes for malformed startxref_CVE-2026-22691

2.7 / 10

LOW

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U

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.

Basic Information

ID CVE-2026-22691

Source GitHub_M

Published Jan 10, 2026 at 04:46

Affected Product

Vendor py-pdf

Product pypdf

Version < 6.6.0

Affected Versions py-pdf pypdf < 6.6.0

CWE Classification

CWE-1333 CWE-400

References

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    "published": "2026-01-10T04:46:12.423Z",
    "modified": "2026-01-10T04:46:12.423Z",
    "type": "cve",
    "title": "pypdf has possible long runtimes for malformed startxref",
    "source": "GitHub_M",
    "references": "https://github.com/py-pdf/pypdf/security/advisories/GHSA-4f6g-68pf-7vhv\nhttps://github.com/py-pdf/pypdf/pull/3594\nhttps://github.com/py-pdf/pypdf/commit/294165726b646bb7799be1cc787f593f2fdbcf45\nhttps://github.com/py-pdf/pypdf/releases/tag/6.6.0",
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