ZDF
Sign inSign up

Vulnerabilities

Vulnerability · CVE-2025-12559

Mattermost versions 11.0.x <= 11.0.2, 10.12.x <= 10.12.1, 10.11.x <= 10.11.4, 10.5.x <= 10.5.12 fail to sanitize team email addresses to be visible only to Team Admins, which allow

Published Nov 27, 2025 · catalog updated Nov 28, 2025 · Mattermost Mattermost

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

Check this week

CVE-2025-12559 is not in CISA KEV. FIRST estimates a 22.00% chance of exploitation in the next 30 days. Check whether you run Mattermost Mattermost.

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
Medium4.3
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
22.00%
Remediation
Advisory link
Affected products
vendor Mattermost Mattermost 10.11.0 ≤10.11.4

Mattermost versions 11.0.x <= 11.0.2, 10.12.x <= 10.12.1, 10.11.x <= 10.11.4, 10.5.x <= 10.5.12 fail to sanitize team email addresses to be visible only to Team Admins, which allows any authenticated user to view team email addresses via the GET /api/v4/channels/{channel_id}/common_teams 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 ≤10.11.410.11.0 ≤10.11.4

How to fix CVE-2025-12559

  • No stored fix

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

  • Version check

    Seen in 10.11.0 ≤10.11.4

  • 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?

CVE-2025-12559 is not in CISA KEV. FIRST estimates a 22.00% chance of exploitation in the next 30 days. Check whether you run Mattermost Mattermost.

Which versions are affected?

Compare what you have installed with Mattermost Mattermost 10.11.0 ≤10.11.4 10.11.0 ≤10.11.4. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

No weakness class is stored. EPSS 22.00%. 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 27, 2025 · EUVD

    Detected

    Mattermost versions 11.0.x <= 11.0.2, 10.12.x <= 10.12.1, 10.11.x <= 10.11.4, 10.5.x <= 10.5.12 fail to sanitize team email addresses to be visible only to Team Admins, which allows any authenticated user to view team email addresses via the GET /api/v4/channels/{channel_id}/common_teams endpoint

  2. Nov 28, 2025 · EUVD

    Updated

    Mattermost versions 11.0.x <= 11.0.2, 10.12.x <= 10.12.1, 10.11.x <= 10.11.4, 10.5.x <= 10.5.12 fail to sanitize team email addresses to be visible only to Team Admins, which allows any authenticated user to view team email addresses via the GET /api/v4/channels/{channel_id}/common_teams endpoint

Sources

  • CVE.orgVulnerability recordCVE-2025-12559

    Official CVE identifier

    cve.org
  • EUVDVulnerability recordEUVD-2025-199831

    Mattermost versions 11.0.x <= 11.0.2, 10.12.x <= 10.12.1, 10.11.x <= 10.11.4, 10.5.x <= 10.5.12 fail to sanitize team email addresses to be visible only to Team Admins, which allows any authenticated user to view team email addresses via the GET /api/v4/channels/{channel_id}/comm

    euvd.enisa.europa.eu

References

Freshness

Last verified in this catalog Nov 28, 2025. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.

  • CVE.orgOct 28, 2026
  • EUVDOct 28, 2026