Mattermost ServerApplication · Mattermost

CVE-2025-47871

MEDIUM · 5.4 CVSS v3.1 Published 2025-06-30
Fix available
A fix is available. Upgrade to 9.11.16 / 10.5.6 or later.
See remediation →
60/100
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 10.5.x <= 10.5.5, 9.11.x <= 9.11.15, 10.8.x <= 10.8.0, 10.7.x <= 10.7.2, 10.6.x <= 10.6.5 fail to properly validate channel membership when retrieving playbook run metadata, allowing authenticated users who are playbook members but not channel members to access sensitive information about linked private channels including channel name, display name, and participant count through the run metadata API endpoint.

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 confidence

Mattermost fails to properly validate channel membership in the playbook run metadata API endpoint. Authenticated users who are playbook members but NOT members of a linked private channel can retrieve sensitive metadata (channel name, display name, participant count) about that private channel through the run metadata API, leading to unauthorized information disclosure.

MitigationUpgrade to Mattermost versions 10.5.6+, 9.11.16+, 10.8.1+, 10.7.3+, 10.6.6+ (or later patched versions) which include proper channel membership validation in the run metadata API endpoint.

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:>= 9.11.0, < 9.11.16>= 10.5.0, < 10.5.6>= 10.6.0, < 10.6.6>= 10.7.0, < 10.7.3= 10.8.0

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
Low
Integrity
Low
Availability
None

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

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

  1. Check Mattermost Server version
    Access the Mattermost System Console > About or run `grep Version /opt/mattermost/config/config.json` or check the Mattermost version via the system console. You can also use the API: GET /api/v4/system/public
    Affected if The installed version falls within one of these ranges: 9.11.0 to 9.11.15, 10.5.0 to 10.5.5, 10.6.0 to 10.6.5, 10.7.0 to 10.7.2, or exactly 10.8.0
  2. Verify Playbooks plugin is enabled
    Navigate to System Console > Plugins > Plugin Management, or query the API at GET /api/v4/plugins
    Affected if The Playbooks plugin is installed and enabled
  3. Identify playbooks with linked private channels
    Query the Playbooks API: GET /api/v1/playbooks to list playbooks, then for each playbook check the channel_id field. Cross-reference channel IDs with private channels using GET /api/v4/channels/{channel_id} and checking the type field equals 'P' for private channels
    Affected if There exist playbooks linked to private channels where the requesting user is a playbook member but not a member of the linked private channel
  4. Test run metadata API for unauthorized disclosure
    As an authenticated user who is a member of a playbook but NOT a member of its linked private channel, make a request to GET /api/v1/playbooks/runs/{run_id}/metadata and inspect the response for the channel field containing private channel details (name, display_name, participant_count)
    Affected if The API response returns channel metadata (channel name, display name, participant count) for a private channel the requesting user is not a member of

If the Mattermost Server version is in the affected list AND the Playbooks plugin is enabled AND there are playbooks linked to private channels, then the environment is vulnerable to unauthorized information disclosure through the run metadata API.

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 9.11.16 / 10.5.6 / 10.6.6 or later
Fixed in 9.11.1610.5.610.6.6
Interim mitigation

Upgrade to Mattermost versions 10.5.6+, 9.11.16+, 10.8.1+, 10.7.3+, 10.6.6+ (or later patched versions) which include proper channel membership validation in the run metadata API endpoint.

Recommended fix High confidence

9.11.16, 10.5.6, 10.6.6, or 10.7.3 depending on your current release branch

  1. 1. Identify current Mattermost Server version by accessing the system console or checking the /about API endpoint
  2. 2. Determine the appropriate target version based on your current major.minor release: 9.11.x users should upgrade to 9.11.16; 10.5.x users should upgrade to 10.5.6; 10.6.x users should upgrade to 10.6.6; 10.7.x users should upgrade to 10.7.3
  3. 3. Create a complete backup of the Mattermost database and config file before upgrading
  4. 4. Test the upgrade in a staging or test environment first
  5. 5. Schedule a maintenance window for the production upgrade
  6. 6. Follow Mattermost upgrade documentation to apply the server update
  7. 7. After upgrade, verify that authenticated playbook members can no longer access private channel metadata they are not members of
Caveat Review Mattermost release notes for your target version to check for any breaking changes or required configuration updates

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
  • Implementation4.0 h
  • Testing4.0 h
  • Review / QA2.0 h
12.0 hours of engineering $2,080
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Scan for this in your stack

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dbcve dependency scanner

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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-2025-47871 in production — separate from our analysis above.

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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
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