CVE-2021-39933: GitLab

Medium severity, CVSS 6.5. EPSS: 1.5% chance of exploitation in the next 30 days.

An issue has been discovered in GitLab CE/EE affecting all versions starting from 12.10 before 14.3.6, all versions starting from 14.4 before 14.4.4, all versions starting from 14.5 before 14.5.2. A regular expression used for handling user input (notes, comments, etc) was susceptible to catastrophic backtracking that could cause a DOS attack.

Affected products

• GitLab GitLab: from 12.10.0, before 14.3.6 (fixed in 14.3.6); from 14.4.0, before 14.4.4 (fixed in 14.4.4); from 14.5.0, before 14.5.2 (fixed in 14.5.2)

Published 2021-12-13. Last modified 2026-06-17.