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
References (1)
Core 1
Core References
Various Sources vendor-advisory
https://mattermost.com/security-updates
Scores
CVSS v3
3.1
EPSS
0.0020
EPSS Percentile
9.8%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N
CISA SSVC
Vulnrichment
Exploitation
none
Automatable
no
Technical Impact
partial
Details
CWE
CWE-367
Status
published
Products (2)
mattermost/mattermost-server
10.11.0 - 10.11.10Go
mattermost/mattermost_server
10.11.0 - 10.11.10
Published
Feb 13, 2026
Tracked Since
Feb 18, 2026