CVE-2025-11777: Mattermost server · Mattermost Incorrect Authorization vulnerability
Affects github.com/mattermost/mattermost-serverSource GCVE Database
Not known to be exploited · CVSS 3.1 Low : upgrade to 10.11.4 when convenient.
Data as of 13 Nov 2026, 18:46 UTC
- Patch
- Available – fixed in 10.11.4, 10.5.12, 8.0.0-20250905150616-ba86dfc5876b +1
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:NExploitation evidence
Disclosed: evidence found.
CVE published 13 Nov 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 13 Nov 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Gogithub.com/mattermost/mattermost-server | Affected
| Fixed in
|
| Gogithub.com/mattermost/mattermost-server | Affected
| Fixed in
|
| Gogithub.com/mattermost/mattermost/server/v8 | Affected
| Fixed in
|
| Gogithub.com/mattermost/mattermost | Affected
| Fixed in
|
| Gogithub.com/mattermost/mattermost-server | Affected
| Fixed in
|
| Gogithub.com/mattermost/mattermost-server/v5 | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Apply the official patches by upgrading to Mattermost server versions 10.11.4, 10.5.12, or the corresponding fixed earlier versions. Since patches are available, remediation should be performed promptly to prevent unauthorized data access.
Description
Mattermost server versions 10.11.0 through 10.11.3 and 10.5.0 through 10.5.11, as well as certain earlier versions, contain an authorization vulnerability in the Add Channel Member API. This flaw allows users from one team to improperly access user metadata and channel membership information from other teams. The issue is due to improper validation of team membership permissions. A fix is available in versions 10.11.4, 10.5.12, and specified earlier versions.
References
- nvd.nist.gov/vuln/detail/CVE-2025-11777 (opens in a new tab)
- github.com/mattermost/mattermost/commit/98acefe911dd9de7edf47a7d825dd99f53141a52 (opens in a new tab)
- github.com/mattermost/mattermost/commit/ba86dfc5876b354b9d3c20ff45c08ca6f8426149 (opens in a new tab)
- github.com/mattermost/mattermost/commit/d72d437f1567ba0b639b6e4fd73bab06c51baab5 (opens in a new tab)
- github.com/mattermost/mattermost (opens in a new tab)
- mattermost.com/security-updates (opens in a new tab)