CVE-2026-21386

4.3 MEDIUM
Published: March 16, 2026 Modified: March 18, 2026
View on NVD

Description

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

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CVSS v3.x Details

0.0 Low Medium High Critical 10.0
Vector String
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N

References to Advisories, Solutions, and Tools

Patch Vendor Advisory Exploit Third Party Advisory
https://mattermost.com/security-updates
Source: responsibledisclosure@mattermost.com
Vendor Advisory

1 reference(s) from NVD

Quick Stats

CVSS v3 Score
4.3 / 10.0
EPSS (Exploit Probability)
0.0%
8th percentile
Exploitation Status
Not in CISA KEV

Weaknesses (CWE)

Affected Vendors

mattermost