CVE-2025-55070: Mattermost server · Mattermost does not enforce MFA on WebSocket connections
Affects github.com/mattermost/mattermost-serverSource GCVE Database
Not known to be exploited · CVSS 6.5 Medium : upgrade to 11.1.0 when convenient.
Data as of 13 Nov 2026, 19:18 UTC
Thin evidence
One scorer or none| CNA (Mattermost) | CVSS 3.1 | 6.5 |
|---|
- Patch
- Available – fixed in 11.1.0, 8.0.0-20250912063506-7d8b7b5e4a60
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/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 to 11.1.0; github.com/mattermost/mattermost/server/v8 to 8.0.0-20250912063506-7d8b7b5e4a60.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Gogithub.com/mattermost/mattermost-server | Affected
| Fixed in
|
| Gogithub.com/mattermost/mattermost/server/v8 | 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 Mattermost server to version 11.1.0 or later, or 8.0.0-20250912063506-7d8b7b5e4a60 or later. This update enforces MFA on WebSocket connections and mitigates the vulnerability. Since a patch is available, remediation should be prioritized to prevent unauthorized data access.
Description
Mattermost server versions prior to 11.1.0 and 8.0.0-20250912063506-7d8b7b5e4a60 do not enforce multi-factor authentication (MFA) on WebSocket connections. This vulnerability allows unauthenticated users to access sensitive information through WebSocket events. The issue has been assigned CVE-2025-55070 and has a medium severity rating with a CVSS score of 6.5. A patch is available in versions 11.1.0 and 8.0.0-20250912063506-7d8b7b5e4a60 that addresses this flaw.