🛡️ CVE-2025-3227 — mattermost-server

🟡 CVSS 4.3 — Medium ✅ No Known Exploit CWE-863 NVD
4.3
CVSS Score
0 Low4 Medium7 High9 Critical10

Description

Mattermost allows unauthorized channel member management through playbook runs

Mattermost versions 10.5.x <= 10.5.5, 9.11.x <= 9.11.15, 10.8.x <= 10.8.0, 10.7.x <= 10.7.2, 10.6.x <= 10.6.5 fail to properly enforce channel member management permissions in playbook runs, allowing authenticated users without the 'Manage Channel Members' permission to add or remove users from public and private channels by manipulating playbook run participants when the run is linked to a channel.

How this vulnerability can be exploited

This issue can be reached over the network, attack complexity is low, an attacker needs low-level privileges on the target. No user interaction is required. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality low, integrity none, availability none.

Weakness class

CVE-2025-3227 is classified as CWE-863: Incorrect Authorization. An authorisation check runs but reaches the wrong conclusion, permitting actions it should refuse.

Affected software

CVE-2025-3227 is recorded against 5 packages.

  • github.com/mattermost/mattermost-server
  • github.com/mattermost/mattermost-server/v5
  • github.com/mattermost/mattermost-server/v6
  • github.com/mattermost/mattermost/server/v8
  • mattermost-server

Timeline and source

Published on 20 June 2025 and last revised on 3 March 2026. No public exploit is currently recorded for this entry. Record sourced from NVD.

References

nvd.nist.gov (Advisory)
github.com (Package)
mattermost.com (Web)

Details

Severity Medium
CVSS Score 4.3
CVSS Vector CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
CWE CWE-863
Public Exploit ✅ No
Source NVD
Published 2025-06-20
Updated 2026-08-12
Modified 2026-03-03
Fix URL N/A

Affected Packages

Software From version Fixed in
github.com/mattermost/mattermost-server — —
github.com/mattermost/mattermost-server/v5 — —
github.com/mattermost/mattermost-server/v6 — —
github.com/mattermost/mattermost/server/v8 — —
mattermost-server — —

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