CVE-2026-16255
Incorrect Authorization in GitLab
Reported by gitlab · Published October 21, 2026
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.
Fixed versions
Upgrade to a fixed version or later. Language registries are listed first, then Linux distributions, then vendor products.
| Package | Ecosystem | Fixed in |
|---|---|---|
| GitLab | GitLab | 19.5.1, 19.4.3, 19.3.6 |
Risk scores
Affected products
| Vendor | Product | Versions |
|---|---|---|
| GitLab | GitLab | 12.0, 19.4, 19.5 |
| GitLab | GitLab | 12.0, 19.4, 19.5 |
Timeline
- Oct 21, 2026 CVE Published
- Oct 22, 2026 EPSS Score (4 in total, the first dated here)
- Oct 30, 2026 CVE Updated
Query this with the API
The same record, from the CLI:
vulnetix vdb vuln CVE-2026-16255
vulnetix vdb fixes CVE-2026-16255Or with curl, using the org id and key from your account page:
curl -s -H "Authorization: ApiKey ${VULNETIX_ORG_ID}:${VULNETIX_API_KEY}" \
"https://api.vdb.vulnetix.com/v2/vuln/CVE-2026-16255/fixes/registry"The Community plan is free and allows 50 queries a day. Get a free API key · API quickstart
References
- HackerOne Bug Bounty Report #3809350 technical-descriptionexploitpermissions-required