CVE-2026-2461 PUBLISHED

Missing authorization check allows unauthorized modification of other users' comments on a board

Assigner: Mattermost
Reserved: 13.02.2026 Published: 16.03.2026 Updated: 16.03.2026

Mattermost Plugins versions <=11.3 11.0.3 11.2.2 10.10.11.0 fail to implement authorisation checks on comment block modifications, which allows an authorised attacker with editor permission to modify comments created by other board members. Mattermost Advisory ID: MMSA-2025-00559

Metrics

CVSS 3.1

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N
CVSS Score: 4.3

Attack Vector	Network	Scope	Unchanged
Attack Complexity	Low	Confidentiality Impact	None
Privileges Required	Low	Integrity Impact	Low
User Interaction	None	Availability Impact	None

CVSS 3.1

Product Status

Vendor	Mattermost
Product	Mattermost
Versions	Default: unaffected affected from 0 to 11.0.3 (incl.) affected from 0 to 11.2.2 (incl.) affected from 0 to 10.10.11 (incl.) Version 11.4.0 is unaffected Version 11.3.1 is unaffected Version 11.2.3 is unaffected Version 10.11.11 is unaffected

Solutions

Update Mattermost Plugins to versions 11.4.0, 11.3.1, 11.2.3, 10.11.11 or higher.

Credits

daynight finder

References

MMSA-2025-00559

Problem Types

CWE-639: Authorization Bypass Through User-Controlled Key CWE