CVE-2026-18223
CVE-2026-18223 · Mattermost invitation tokens not bound to invited email address allowing unauthorized team and private channel access
This page contains facts from public vulnerability sources. Check the original advisory before updating.
Mattermost versions 11.10.x <= 11.10.0, 11.7.x <= 11.7.9, 11.9.x <= 11.9.1, 11.8.x <= 11.8.5 fail to validate the invited recipient's email address when redeeming team and guest invitation tokens, which allows an authenticated attacker to join a team or gain unauthorized access to private channels via a forwarded or leaked invitation link.. Mattermost Advisory ID: MMSA-2026-00747
CVSS 5.0 · Medium · EPSS 0.2% · Fix available
- Published
- Updated
Affected products and versions
mattermost
- Versions
- ≥ 11.10.0, ≤ 11.10.0: Affected (semver)
- ≥ 11.7.0, ≤ 11.7.9: Affected (semver)
- ≥ 11.9.0, ≤ 11.9.1: Affected (semver)
- ≥ 11.8.0, ≤ 11.8.5: Affected (semver)
- 11.11.0: Not affected
- 11.10.1: Not affected
- 11.7.10: Not affected
- 11.9.2: Not affected
- 11.8.6: Not affected
Update to 11.10.1; Update to 11.7.10; Update to 11.8.6; Update to 11.9.2