CVE-2021-26910: Debian Linux

High severity, CVSS 7.0. EPSS: 0.4% chance of exploitation in the next 30 days.

Firejail before 0.9.64.4 allows attackers to bypass intended access restrictions because there is a TOCTOU race condition between a stat operation and an OverlayFS mount operation.

Affected products

• Debian Debian Linux: version 9.0 only; version 10.0 only
• Firejail Project Firejail: before 0.9.64.4 (fixed in 0.9.64.4)

Published 2021-02-08. Last modified 2026-06-17.