PT-2026-51380 · Py Pdf · Pypdf

Published 2026-06-22 · Updated 2026-06-22 · CVE-2026-54651

Mitre

CVSS v4.0

6.9

Medium

Base vector

AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

pypdf is a free and open-source pure-python PDF library. Prior to 6.13.1, an attacker who uses this vulnerability can craft a PDF which leads to an infinite loop. This requires merging a file with threads/articles into a writer. This vulnerability is fixed in 6.13.1.

Fix

Infinite Loop

Weakness Enumeration

CWE-835

Related Identifiers

CVE-2026-54651

Affected Products

Pypdf

References · 4

• https://nvd.nist.gov/vuln/detail/CVE-2026-54651 · Security Note
• https://github.com/py-pdf/pypdf/pull/3839 · Note
• https://github.com/py-pdf/pypdf/releases/tag/6.13.1 · Note
• https://github.com/py-pdf/pypdf/security/advisories/GHSA-g9xf-7f8q-9mcj · Note