Improper Access Control in Mattermost's Playbooks
CVE-2026-6343

4.3MEDIUM

Key Information:

Vendor

Mattermost
Status
Mattermost
Vendor
CVE Published:
18 May 2026

What is CVE-2026-6343?

Mattermost versions 11.5.x through 11.5.1, 10.11.x through 10.11.13, and 11.4.x through 11.4.3 are vulnerable due to improper access control mechanisms. This vulnerability allows users without appropriate permissions to access public playbooks via the /get endpoint, potentially exposing sensitive operational details. Users are advised to review their configurations and apply necessary updates to safeguard their systems.

Affected Version(s)

Mattermost 11.5.0 <= 11.5.1

Mattermost 10.11.0 <= 10.11.13

Mattermost 11.4.0 <= 11.4.3

References

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

CVSS V3.1

Score:
4.3
Severity:
MEDIUM
Confidentiality:
Low
Integrity:
None
Availability:
Low
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
Low
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

0x7oda7123
.