CVE-2026-16255
Medium
Description
GitLab has remediated an issue in GitLab EE affecting all versions from 12.0 before 19.3.6, 19.4 before 19.4.3, and 19.5 before 19.5.1 that, when the instance-wide SAML or LDAP membership lock was enabled, an authenticated user could have granted or accepted project and group membership outside the identity provider's control, due to incomplete enforcement of the membership lock on requests created before the lock was enabled.
SeverityMedium
CVSS5.9
Exploit probability—
Product
Gitlab
PublishedOct 22, 2026
First seenOct 22, 2026
Weakness typeCWE-863Incorrect authorization
How to fix
Update
- gitlab gitlab19.3.6, 19.4.3 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| gitlab gitlab | 12.0.0 ≤ v < 19.3.6, 19.4.0 ≤ v < 19.4.3, 19.5.0 | 19.3.6, 19.4.3 |
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