CVE-2025-40908: Ingydotnet Yaml-Libyaml

Critical severity, CVSS 9.1. EPSS: 0.5% chance of exploitation in the next 30 days.

YAML-LibYAML prior to 0.903.0 for Perl uses 2-args open, allowing existing files to be modified

Affected products

• Ingydotnet Yaml-Libyaml: before 0.903.0 (fixed in 0.903.0)

Published 2025-06-01. Last modified 2026-06-17.