CVE-2025-11777
LOWMattermost 10.5.0-10.5.11 and 10.11.0-10.11.3 - Incorrect Authorization via Add Channel Member API
Title source: llmDescription
Mattermost versions 10.11.x <= 10.11.3, 10.5.x <= 10.5.11 fail to properly validate team membership permissions in the Add Channel Member API which allows users from one team to access user metadata and channel membership information from other teams via the API endpoint
References (1)
Core 1
Core References
Vendor Advisory
https://mattermost.com/security-updates
Scores
CVSS v3
3.1
EPSS
0.0003
EPSS Percentile
8.0%
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-863
Status
published
Products (5)
mattermost/mattermost
0 - 5.3.2-0.20250905150616-ba86dfc5876bGo
mattermost/mattermost
0 - 8.0.0-20250905150616-ba86dfc5876bGo
mattermost/mattermost-server
0 - 5.3.2-0.20250905150616-ba86dfc5876b (2 CPE variants)Go
mattermost/mattermost-server
10.11.0 - 10.11.4Go
mattermost/mattermost_server
10.5.0 - 10.5.12
Published
Nov 13, 2025
Tracked Since
Feb 18, 2026