Mattermost
CVE-2025-55070
MEDIUM
Vulnerability Assessment
| Weakness |
CWE
OWASP Top 10:2025
A07:2025 - Authentication Failures
ASVS 5.0
V6 - Authentication Authentication required for critical functions
MITRE ATT&CK
1 technique across 1 tactic: Initial Access The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. |
| Impact | CVSS score of 6.5 (MEDIUM). Attack characteristics: network attack vector, low complexity, low privileges required, no user interaction not required. EPSS exploitation probability: 0.15%. |
| Exploit ScenarioDerived | A remote attacker could access critical functionality without authentication by sending crafted requests to the affected application. |
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Alert meAnalysisAIv1 – Mar 28, 2026
Mattermost versions <11 fail to enforce multi-factor authentication on WebSocket connections which allows unauthenticated users to access sensitive information via WebSocket events. Rated medium severity (CVSS 6.5), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
RemediationAI
No vendor patch is available at time of analysis. Monitor vendor advisories for updates. Require authentication for all sensitive operations, implement defense in depth.
Affected Packages
Source: OSV (Open Source Vulnerabilities)
Affects your stack
Affects 4 packages in go
Checking this CVE against your own stacks and servers is part of the Basic plan and up.
Technical ContextAI · show details
This vulnerability is classified as Missing Authentication for Critical Function (CWE-306), which allows attackers to access critical functionality without authentication. Mattermost versions <11 fail to enforce multi-factor authentication on WebSocket connections which allows unauthenticated users to access sensitive information via WebSocket events Affected products include: Mattermost Mattermost Server.
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Severity by source
AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
Primary rating from NVD.
CVSS VectorNVD
Lifecycle Timeline
2DescriptionCVE.org
Mattermost versions <11 fail to enforce multi-factor authentication on WebSocket connections which allows unauthenticated users to access sensitive information via WebSocket events
Executive ViewAI
CVE-2025-55070 presents notable security risk, a missing authentication vulnerability rated CVSS 6.5. This could allow unauthorized access to protected resources. Organizations should apply vendor updates when available and monitor for exploitation.
Apply vendor patch. If patching is delayed: restrict network access, enable MFA, monitor auth logs.
Threat Intelligence Overview
How this decision was reached
The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.
What every action level means
SSVC AssessmentENISA
Priority Score
Attack Technique
Authentication bypass attacks exploit flaws in the verification mechanisms that control access to systems and applications.
Affected Products (CPE)CVE.org
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GitHub PoC
Exploit-DB