CVE-2026-24688: Pypdf Project Pypdf

Medium severity, CVSS 4.3. EPSS: 0.5% chance of exploitation in the next 30 days.

pypdf is a free and open-source pure-python PDF library. An attacker who uses an infinite loop vulnerability that is present in versions prior to 6.6.2 can craft a PDF which leads to an infinite loop. This requires accessing the outlines/bookmarks. This has been fixed in pypdf 6.6.2. If projects cannot upgrade yet, consider applying the changes from PR #3610 manually.

Affected products

• Pypdf Project Pypdf: before 6.6.2 (fixed in 6.6.2)

Published 2026-01-27. Last modified 2026-06-17.