An input validation and output encoding issue was discovered in the GitLab email notification feature which could result in a persistent XSS. This was addressed in GitLab 12.1.2, 12.0.4, and 11.11.6.
Severity
CVSS 3.1
5.4 medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
EPSS
0.8% chance of exploitation in the next 30 days; higher than 56% of CVEs (scores of 2026-10-31)