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Mattermost EUVDEUVD-2026-12437

| CVE-2026-21386 MEDIUM
Observable Discrepancy (CWE-203)
2026-03-16 responsibledisclosure@mattermost.com GHSA-5mr9-crcg-8wh2
4.3
CVSS 3.1 · NVD
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Severity by source

NVD PRIMARY
4.3 MEDIUM
AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
SUSE
MEDIUM
qualitative

Primary rating from NVD.

CVSS VectorNVD

Attack Vector
Network
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
None
Availability
None

Lifecycle Timeline

4
Patch released
Mar 31, 2026 - 21:13 nvd
Patch available
EUVD ID Assigned
Mar 16, 2026 - 15:30 euvd
EUVD-2026-12437
Analysis Generated
Mar 16, 2026 - 15:30 vuln.today
CVE Published
Mar 16, 2026 - 15:16 nvd
MEDIUM 4.3

DescriptionCVE.org

Mattermost versions 11.3.x <= 11.3.0, 11.2.x <= 11.2.2, 10.11.x <= 10.11.10 fail to use consistent error responses when handling the /mute command which allows an authenticated team member to enumerate private channels they are not authorized to know about via differing error messages for nonexistent versus private channels. Mattermost Advisory ID: MMSA-2026-00588

AnalysisAI

CVE-2026-21386 is a security vulnerability (CVSS 4.3) that allows an authenticated team member. Remediation should follow standard vulnerability management procedures.

Technical ContextAI

Vulnerability type not specified by vendor.

RemediationAI

Monitor vendor channels for patch availability.

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CVE-2025-12419 CRITICAL
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Mattermost versions 10.4.x <= 10.4.1, 9.11.x <= 9.11.7, 10.3.x <= 10.3.2, 10.2.x <= 10.2.2 fail to use prepared statemen

Vendor StatusVendor

SUSE

Severity: Medium
Product Status
openSUSE Leap 15.6 Fixed
SUSE Linux Enterprise Module for Package Hub 15 SP5 Fixed
SUSE Linux Enterprise Module for Package Hub 15 SP6 Fixed
openSUSE Leap 15.5 Fixed

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EUVD-2026-12437 vulnerability details – vuln.today

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