Channel Role Assignment Vulnerability in Mattermost by Mattermost
CVE-2026-16048

6.3MEDIUM

Key Information:

Vendor

Mattermost
Status
Mattermost
Vendor
CVE Published:
17 August 2026

What is CVE-2026-16048?

A vulnerability in Mattermost allows channel administrators to improperly assign roles to channel members, leading to unauthorized access to additional permissions through the channel member roles API. This affects versions 11.8.x up to 11.8.2, 11.7.x up to 11.7.6, and 10.11.x up to 10.11.21, potentially compromising the integrity of channel permissions.

Affected Version(s)

Mattermost 11.8.0 <= 11.8.2

Mattermost 11.7.0 <= 11.7.6

Mattermost 10.11.0 <= 10.11.21

References

https://mattermost.com/security-updates
vendor-advisory

CVSS V3.1

Score:
6.3
Severity:
MEDIUM
Confidentiality:
Low
Integrity:
Low
Availability:
Low
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
Low
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

LePipouDesBois
.