CVE-2025-55070
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedMattermost versions <11 fail to enforce multi-factor authentication on WebSocket connections which allows unauthenticated users to access sensitive information via WebSocket events
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceMattermost versions prior to 11 fail to enforce multi-factor authentication on WebSocket connections, allowing unauthenticated users to intercept sensitive information through WebSocket events.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data< 11.0.0CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- None
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Identify the installed Mattermost Server versionRun 'mattermost version' or check the about section in the System Console, or inspect the binary/version fileAffected if The installed version is below 11.0.0 (e.g., 10.x, 9.x, etc.)
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Confirm WebSocket connections are enabledCheck the Mattermost configuration file (config.json) for 'EnableWebSocket' setting or inspect System Console > Environment > WebSocketAffected if WebSocket is enabled and the server version is below 11.0.0
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Determine if the server accepts external WebSocket connectionsReview the WebSocket endpoint configuration and network settings to see if WebSocket ports are exposed externallyAffected if The WebSocket endpoint is accessible externally and the server version is below 11.0.0, allowing potential unauthenticated access
You are affected if your Mattermost Server is version 10.x or lower AND WebSocket connections are enabled in your environment, because the CVE indicates versions prior to 11.0.0 do not enforce MFA on WebSocket connections.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scoped11.0.0
Upgrade Mattermost to version 11 or later to enforce MFA on WebSocket connections, and verify the configuration is correctly applied.
Mattermost Server 11.0.0 or later
- 1. Back up your current Mattermost Server database and configuration files
- 2. Download Mattermost Server version 11.0.0 or later from the official Mattermost downloads page (mattermost.com)
- 3. Follow the official Mattermost upgrade documentation for your deployment method (e.g., Docker, Ansible, manual upgrade)
- 4. After upgrade, verify that WebSocket connections now properly enforce multi-factor authentication
- 5. Test that legitimate users with MFA enabled can still establish WebSocket connections successfully
- 6. Monitor logs to confirm unauthenticated WebSocket access attempts are now rejected
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 h
- Implementation4.0 h
- Testing3.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,088.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2025-55070 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2025-55070 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.
- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
- No spam, self-promotion, credentials, or personal data