CVE-2026-20796CWE-367

Time-of-check time-of-use vulnerability in common teams API

Low · published February 13, 2026

CVSS v3.1
3.1
EPSS
0%
Percentile
11.8
In the wild
Unconfirmed
What it is

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

The record
Technical detail
CVSS v3.1
3.1 · LOW
Vector
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N
CVSS v4.0
Not supplied
EPSS
0.00220 · 11.8th percentile
Weakness
CWE-367 · Time-of-check Time-of-use (TOCTOU) Race Condition
Published
2026-02-13T10:30Z
EPSS history
Timeline
  • 13 FEB 10:30Z
    Time-of-check time-of-use vulnerability in common teams API
    cvelistv5