Description
Mattermost versions 11.7.x <= 11.7.6, 10.11.x <= 10.11.21 fail to prevent guest users from receiving Board Admin privileges during board archive import which allows a board member to escalate a guest user to Board Admin via importing a crafted .boardarchive file. Mattermost Advisory ID: MMSA-2026-00672
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Mattermost | Mattermost | 11.7.0 – ≤ 11.7.6, 10.11.0 – ≤ 10.11.21 | 11.9.0 |
Advisories 2
- NCSC-2026-0305 Kwetsbaarheden verholpen in Mattermost NCSC-NL (Netherlands) · Aug 19, 2026
- WID-SEC-2026-2411 Mattermost: Mehrere Schwachstellen ermöglichen nicht spezifizierten Angriff BSI CERT-Bund (WID) · Aug 17, 2026
References
- MMSA-2026-00672 vendor-advisory