CVE-2026-20796

3.1 LOW
Published: February 13, 2026 Modified: February 23, 2026
View on NVD

Description

Mattermost versions 10.11.x <= 10.11.9 fail to properly validate channel membership at the time of data retrieval which allows a deactivated user to learn team names they should not have access to via a race condition in the /common_teams API endpoint.. Mattermost Advisory ID: MMSA-2025-00549

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CVSS v3.x Details

0.0 Low Medium High Critical 10.0
Vector String
CVSS:3.1/AV:N/AC:H/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
3.1 / 10.0
EPSS (Exploit Probability)
0.0%
1th percentile
Exploitation Status
Not in CISA KEV

Weaknesses (CWE)

Affected Vendors

mattermost