What is the CVSS score of CVE-2025-12559?

CVE-2025-12559 has a CVSS 3.1 base score of 4.3 (Medium). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N. EPSS exploitation probability: 0.0%.

Which versions of Mattermost Server are affected by CVE-2025-12559?

CVE-2025-12559 presents moderate security risk, a information exposure vulnerability rated CVSS 4.3. Sensitive information could be exposed to unauthorized parties.. A patch is available.

How to fix or mitigate CVE-2025-12559?

Within 30 days: Identify affected systems and apply vendor patches as part of regular patch cycle. Review data exposure and access controls.

Mattermost Server CVE-2025-12559

MEDIUM

Information Exposure (CWE-200)

2025-11-27 responsibledisclosure@mattermost.com

Information Disclosure Mattermost Server Suse

4.3

CVSS 3.1

CVSS VectorNVD

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

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

Low

Integrity

None

Availability

None

Lifecycle Timeline

Patch released

Mar 31, 2026 - 21:13 nvd

Patch available

Analysis Generated

Mar 28, 2026 - 19:24 vuln.today

CVE Published

Nov 27, 2025 - 17:15 nvd

MEDIUM 4.3

DescriptionNVD

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

AnalysisAI

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. Rated medium severity (CVSS 4.3), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.

Technical ContextAI

This vulnerability is classified as Exposure of Sensitive Information (CWE-200), which allows attackers to access sensitive data that should not be disclosed. 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 Affected products include: Mattermost Mattermost Server.

RemediationAI

No vendor patch is available at time of analysis. Monitor vendor advisories for updates. Minimize information in error messages, implement proper access controls, encrypt sensitive data at rest and in transit.

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CVE-2025-12559 vulnerability details – vuln.today

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Mattermost Server CVE-2025-12559

CVSS VectorNVD

Lifecycle Timeline

DescriptionNVD

AnalysisAI

Technical ContextAI

RemediationAI

More from same product – last 7 days

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External POC / Exploit Code