1. Home
  2. CVE Database
  3. CVE-2026-6342
MEDIUM · 4.3

CVE-2026-6342

Mattermost Plugins versions <=11.5 11.1.5 10.13.11 11.3.4.0 fail to appropriately check for valid namespaces which allows plugin users to create subscriptions to groups that were not whitelisted via c...

Vulnerability Description

Mattermost Plugins versions <=11.5 11.1.5 10.13.11 11.3.4.0 fail to appropriately check for valid namespaces which allows plugin users to create subscriptions to groups that were not whitelisted via creating groups that share the same prefix as a whitelisted group. Mattermost Advisory ID: MMSA-2026-00601

CVSS Score

4.3

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
LOW
Availability
NONE

Affected Products

VendorProductVersions
MattermostMattermost Server>= 10.13.0, <= 10.13.11

Related Weaknesses (CWE)

CWE-863

References

FAQ

What is CVE-2026-6342?

CVE-2026-6342 is a vulnerability with a CVSS score of 4.3 (MEDIUM). Mattermost Plugins versions <=11.5 11.1.5 10.13.11 11.3.4.0 fail to appropriately check for valid namespaces which allows plugin users to create subscriptions to groups that were not whitelisted via c...

How severe is CVE-2026-6342?

CVE-2026-6342 has been rated MEDIUM with a CVSS base score of 4.3/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2026-6342?

Check the references section above for vendor advisories and patch information. Affected products include: Mattermost Mattermost Server.