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Mattermost ServerApplication · Mattermost

CVE-2025-14435

MEDIUM · 6.5 CVSS v3.1 Published 2026-01-16
Fix available
A fix is available. Upgrade to 10.11.9 / 11.0.7 or later.
See remediation →
71/100
Remediation priority · Elevated
Remotely reachable Zero-click

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 · unedited
Mattermost versions 10.11.x <= 10.11.8, 11.1.x <= 11.1.1, 11.0.x <= 11.0.6 fail to prevent infinite re-renders on API errors which allows authenticated users to cause application-level DoS via triggering unbounded component re-render loops.

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 · moderate confidence

Mattermost fails to prevent infinite re-renders on API errors, allowing authenticated users to trigger unbounded component re-render loops that cause application-level denial of service.

MitigationUpgrade to Mattermost version 10.11.9, 11.1.2, 11.0.7, or later which contain the fix for this vulnerability.

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
Mattermost ServerApplication
Affected:>= 10.11.0, < 10.11.9>= 11.0.0, < 11.0.7>= 11.1.0, < 11.1.2

CVSS 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
Low
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

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 checks

Work through these to decide whether this CVE applies to you.

  1. Check Mattermost Server version
    Access the Mattermost System Console > About > Mattermost, or query the API endpoint GET /api/v4/system/config, or run 'mattermost version' from the server CLI if you have direct access.
    Affected if The displayed version falls within these ranges: 10.11.0 through 10.11.8, 11.0.0 through 11.0.6, or 11.1.0 through 11.1.1.
  2. Confirm authenticated user access
    Verify that the Mattermost deployment allows user authentication. Check if local accounts, LDAP/Active Directory, or SSO providers are enabled in Authentication settings.
    Affected if Authenticated user accounts exist or can be created, as the vulnerability requires an authenticated user to trigger the infinite re-render via API errors.
  3. Review server logs for re-render indicators
    Examine Mattermost server logs (typically in /var/log/mattermost/ or via the System Console > Logs) for repeated entries of the same API error or component warnings occurring in rapid succession.
    Affected if Logs show a high frequency of identical API error messages or component re-render warnings within short time periods, indicating a potential exploitation attempt.
  4. Check webapp component versions (optional)
    If you have access to the Mattermost source or deployed files, verify the webapp package version in the mattermost-webapp package.json or the compiled static files, as the fix addresses client-side component behavior.
    Affected if The bundled webapp version matches the affected server version ranges and has not been patched separately.

You are affected if your Mattermost Server version is 10.11.0-10.11.8, 11.0.0-11.0.6, or 11.1.0-11.1.1 and you have authenticated users who can interact with the application.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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 · scoped
Upgrade available Upgrade to 10.11.9 / 11.0.7 / 11.1.2 or later
Fixed in 10.11.911.0.711.1.2
Interim mitigation

Upgrade to Mattermost version 10.11.9, 11.1.2, 11.0.7, or later which contain the fix for this vulnerability.

Recommended fix High confidence

Upgrade to Mattermost Server 10.11.9, 11.0.7, or 11.1.2 (select the appropriate version for your current major version branch)

  1. Back up your Mattermost database and configuration files before upgrading
  2. Stop the Mattermost Server service
  3. Upgrade Mattermost Server to version 10.11.9, 11.0.7, or 11.1.2 (depending on your current major version branch)
  4. Verify the upgrade was successful by checking the server version
  5. Restart the Mattermost Server service
  6. Monitor system performance to confirm the infinite re-render issue is resolved

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Mattermost Server Scoped from the published advisory
  • Consultation2.0 h
  • Implementation8.0 h
  • Testing4.0 h
  • Review / QA2.0 h
16.0 hours of engineering $2,800
Get the upgrade done

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Scan for this in your stack

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2025-14435 in production — separate from our analysis above.

No notes yet

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What this is

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.

What belongs here
  • 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