CVE-2025-10545

LOW

Mattermost 10.5.0-10.5.10 and 10.11.0-10.11.2 - Incorrect Authorization via Channel Member Endpoint

Title source: llm

Description

Mattermost versions 10.5.x <= 10.5.10, 10.11.x <= 10.11.2 fail to properly validate guest user permissions when adding channel members which allows guest users to add any team members to their private channels via the `/api/v4/channels/{channel_id}/members` endpoint

References (1)

Core 1

Core References

Vendor Advisory

https://mattermost.com/security-updates

Scores

CVSS v3 3.1

EPSS 0.0001

EPSS Percentile 0.9%

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 (3)

mattermost/mattermost 0 - 8.0.0-20250820115038-ff30b84049f0Go

mattermost/mattermost-server 10.5.0 - 10.5.11Go

mattermost/mattermost_server 10.5.0 - 10.5.11

Published Oct 16, 2025

Tracked Since Feb 18, 2026