CVE-2025-11776: V8 · Mattermost fails to properly restrict access to archived channel search API
Affects github.com/mattermost/mattermost/server/v8Source GCVE Database
Not known to be exploited · CVSS 4.3 Medium : upgrade to 8.0.0-20250815165020-c8d66301415d when convenient.
Data as of 13 Nov 2026, 19:03 UTC
Thin evidence
One scorer or none| CNA (Mattermost) | CVSS 3.1 | 4.3 |
|---|
- Patch
- Available – fixed in 8.0.0-20250815165020-c8d66301415d, 5.3.2-0.20250815165020-c8d66301415d
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:NExploitation evidence
Disclosed: evidence found.
CVE published 14 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 github.com/mattermost/mattermost/server/v8 to 8.0.0-20250815165020-c8d66301415d; github.com/mattermost/mattermost and github.com/mattermost/mattermost-server and github.com/mattermost/mattermost-server/v5 and github.com/mattermost/mattermost-server/v6 to 5.3.2-0.20250815165020-c8d66301415d.
Affected software
| Product | 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
|
| Gogithub.com/mattermost/mattermost-server/v6 | 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
A patch is available and has been released in Mattermost versions 8.0.0-20250815165020-c8d66301415d and 5.3.2-0.20250815165020-c8d66301415d. Users should upgrade to these versions or later to remediate this vulnerability.
Description
Mattermost versions prior to 8.0.0-20250815165020-c8d66301415d and 5.3.2-0.20250815165020-c8d66301415d have a vulnerability where guest users can access the archived channel search API without proper restrictions. This allows discovery of archived public channels via the /api/v4/teams/{team_id}/channels/search_archived endpoint. The issue is fixed in the specified versions.