GitLab 12.2.2 and below contains a security vulnerability that allows a guest user in a private project to see the merge request ID associated to an issue via the activity timeline.
Severity
CVSS 3.1
4.3 medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
EPSS
1.0% chance of exploitation in the next 30 days; higher than 63% of CVEs (scores of 2026-10-31)