CVE-2026-3115CWE-863

Guest users can view group member IDs without respecting view restrictions

Medium · published March 26, 2026

CVSS v3.1
4.3
EPSS
0%
Percentile
18.2
In the wild
Unconfirmed
What it is

Mattermost versions 11.2.x <= 11.2.2, 10.11.x <= 10.11.10, 11.4.x <= 11.4.0, 11.3.x <= 11.3.1 fail to apply view restrictions when retrieving group member IDs, which allows authenticated guest users to enumerate user IDs outside their allowed visibility scope via the group retrieval endpoint.. Mattermost Advisory ID: MMSA-2026-00594

The record
Technical detail
CVSS v3.1
4.3 · MEDIUM
Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
CVSS v4.0
Not supplied
EPSS
0.00270 · 18.2th percentile
Weakness
CWE-863 · Incorrect Authorization
Published
2026-03-26T16:23Z
EPSS history
Timeline
  • 26 MAR 16:23Z
    Guest users can view group member IDs without respecting view restrictions
    cvelistv5