SecuriTricks - CVE-2026-6689

Description

Mattermost versions 11.6.x <= 11.6.1, 11.5.x <= 11.5.4, 10.11.x <= 10.11.15, 10.11.x <= 10.11.16 Fail to enforce PermissionInviteUser when setting AllowOpenInvite or AllowedDomains during team creation (the check was only applied on update/patch), which allows an authenticated user holding PermissionCreateTeam but not PermissionInviteUser on the resulting team to configure invite-controlled team settings (make the team publicly joinable via open invite and/or constrain membership via allowed domains) that they are not permitted to set on an existing team via POST /api/v4/teams with allow_open_invite: true and/or a non-empty allowed_domains in the request body.. Mattermost Advisory ID: MMSA-2026-00655

Product(s) Impacted

Vendor	Product	Versions
Mattermost	Mattermost	11.6., 11.5., 10.11.*

Weaknesses

Common security weaknesses mapped to this vulnerability.

CWE-862

Missing Authorization

The product does not perform an authorization check when an actor attempts to access a resource or perform an action.

*CPE(s)

Affected systems and software identified for this CVE.

Type	Vendor	Product	Version	Update	Edition	Language	Software Edition	Target Software	Target Hardware	Other Information
a	mattermost	mattermost	11.6.*	/	/	/	/	/	/	/
a	mattermost	mattermost	11.5.*	/	/	/	/	/	/	/
a	mattermost	mattermost	10.11.*	/	/	/	/	/	/	/

References

https://mattermost.com/security-updates

CVSS Score

4.3 / 10

CVSS Data - 3.1

Attack Vector: NETWORK
Attack Complexity: LOW
Privileges Required: LOW
Scope: UNCHANGED
Confidentiality Impact: NONE
Integrity Impact: LOW
Availability Impact: NONE

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

View Vector String

Timeline

Published: June 12, 2026, 5:16 p.m.
Last Modified: June 12, 2026, 5:16 p.m.

Status : Received

CVE has been recently published to the CVE List and has been received by the NVD.

More info

Source

[email protected]

CVE-2026-6689