CVE-2026-48156: Pypdf Project Pypdf

Low severity, CVSS 3.3. EPSS: 0.2% chance of exploitation in the next 30 days.

pypdf is a free and open-source pure-python PDF library. Prior to 6.12.0, an attacker who uses this vulnerability can craft a PDF which leads to long runtimes. This requires cross-reference streams with /W [0 0 0] values and large /Size values. This vulnerability is fixed in 6.12.0.

Affected products

• Pypdf Project Pypdf: before 6.12.0 (fixed in 6.12.0)

Published 2026-05-28. Last modified 2026-06-17.