CVE-2026-27888: Pypdf Project Pypdf

High severity, CVSS 7.5. EPSS: 0.6% chance of exploitation in the next 30 days.

pypdf is a free and open-source pure-python PDF library. Prior to 6.7.3, an attacker who uses this vulnerability can craft a PDF which leads to the RAM being exhausted. This requires accessing the `xfa` property of a reader or writer and the corresponding stream being compressed using `/FlateDecode`. This has been fixed in pypdf 6.7.3. As a workaround, apply the patch manually.

Affected products

• Pypdf Project Pypdf: before 6.7.3 (fixed in 6.7.3)

Published 2026-02-26. Last modified 2026-06-17.