CVE-2026-9820

LOW

Mattermost schemes teams endpoint exposes private team invite IDs

Title source: cna
STIX 2.1

Description

Mattermost versions 11.7.x <= 11.7.2, 10.11.x <= 10.11.19 fail to sanitize team objects returned by the scheme teams endpoint, which allows a user with the User Manager role to obtain invite links for private teams and use them to join or share access to those teams via the scheme teams API endpoint.. Mattermost Advisory ID: MMSA-2026-00671

References (1)

Core 1
Core References
Vendor Advisory vendor-advisory
MMSA-2026-00671
https://mattermost.com/security-updates

Scores

CVSS v3 3.8
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:N

CISA SSVC

Vulnrichment
Exploitation none
Automatable no
Technical Impact partial

Details

CWE
CWE-862
Status published
Products (6)
Mattermost/Mattermost 10.11.0 - 10.11.19
Mattermost/Mattermost 10.11.20
Mattermost/Mattermost 11.7.0 - 11.7.2
Mattermost/Mattermost 11.7.3
Mattermost/Mattermost 11.8.0
mattermost/mattermost_server 10.11.0 - 10.11.20
Published Jul 13, 2026
Tracked Since Jul 13, 2026