ZDF
Sign inSign up

Vulnerabilities

Vulnerability · CVE-2025-11777

Mattermost versions 10.11.x <= 10.11.3, 10.5.x <= 10.5.11 fail to properly validate team membership permissions in the Add Channel Member API which allows users from one team to ac

Published Nov 13, 2025 · catalog updated Nov 13, 2025 · Mattermost Mattermost

Last checked Oct 28, 2026. A connected source was read within the last 7 days.

Check if you run it

No confirmed exploitation is on record for CVE-2025-11777. EPSS is 0.20%. Act only if a listed version of Mattermost Mattermost is installed.

Gaps on this record

  • No vendor fix or required action is stored. Compare the linked advisory before you change production.

Same product and reporting

Severity
Low3.1
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.20%
Remediation
Advisory link
Affected products
vendor Mattermost Mattermost 10.11.0 ≤10.11.3

Mattermost versions 10.11.x <= 10.11.3, 10.5.x <= 10.5.11 fail to properly validate team membership permissions in the Add Channel Member API which allows users from one team to access user metadata and channel membership information from other teams via the API endpoint

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • vendor Mattermost Mattermost 10.11.0 ≤10.11.310.11.0 ≤10.11.3

How to fix CVE-2025-11777

  • No stored fix

    No vendor fix text is stored. Use the linked advisory before you change production.

  • Version check

    Seen in 10.11.0 ≤10.11.3

  • Advisory

    Open the cve_org record and follow its fix.

  • Official advisories

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2025-11777. EPSS is 0.20%. Act only if a listed version of Mattermost Mattermost is installed.

Which versions are affected?

Compare what you have installed with Mattermost Mattermost 10.11.0 ≤10.11.3 10.11.0 ≤10.11.3. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

No weakness class is stored. EPSS 0.20%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

No public source repository is identified for this product.

Timeline

Detection, updates, and resolution for this record.

  1. Nov 13, 2025 · EUVD

    Detected

    Mattermost versions 10.11.x <= 10.11.3, 10.5.x <= 10.5.11 fail to properly validate team membership permissions in the Add Channel Member API which allows users from one team to access user metadata and channel membership information from other teams via the API endpoint

  2. Nov 13, 2025 · EUVD

    Updated

    Mattermost versions 10.11.x <= 10.11.3, 10.5.x <= 10.5.11 fail to properly validate team membership permissions in the Add Channel Member API which allows users from one team to access user metadata and channel membership information from other teams via the API endpoint

Sources

  • CVE.orgVulnerability recordCVE-2025-11777

    Official CVE identifier

    cve.org
  • EUVDVulnerability recordEUVD-2025-175343

    Mattermost versions 10.11.x <= 10.11.3, 10.5.x <= 10.5.11 fail to properly validate team membership permissions in the Add Channel Member API which allows users from one team to access user metadata and channel membership information from other teams via the API endpoint

    euvd.enisa.europa.eu

References

Freshness

Last verified in this catalog Oct 28, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.

  • CVE.orgOct 25, 2026
  • EUVDOct 25, 2026