CVEvulnerability

CVE-2026-4274

5.4 MEDIUM Published 2026-03-26 Modified 2026-06-17 Official page ↗
Status
Analyzed
Published
2026-03-26
Last modified
2026-06-17
Assigner
[email protected]
CVSS 3.1 ([email protected])
5.4 MEDIUM — CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N
Weaknesses
CWE-863

Description

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 restrict team-level access when processing membership sync from a remote cluster, which allows a malicious remote cluster to grant a user access to an entire private team instead of only the shared channel via sending crafted membership sync messages that trigger team membership assignment. Mattermost Advisory ID: MMSA-2026-00574

Affected configurations

• mattermost mattermost server (>= 10.11.0 < 10.11.11) • mattermost mattermost server (>= 11.2.0 < 11.2.3) • mattermost mattermost server (>= 11.3.0 < 11.3.2) • mattermost mattermost server (>= 11.4.0 < 11.4.1)

Related

Weakness · CWE (1)

  • CWE-863 Incorrect Authorization weakness

References