Mattermost up to 11.6.x Setting authorization

CVSS Meta Temp Score
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CTI Interest Score
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4.2$0-$5k2.70

Summaryinfo

A vulnerability was found in Mattermost up to 10.11.15/10.11.16/11.5.4/11.6.1/11.6.x. It has been classified as problematic. This issue affects some unknown processing of the component Setting Handler. This manipulation causes authorization. This vulnerability is tracked as CVE-2026-6689. The attack is possible to be carried out remotely. No exploit exists. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability was found in Mattermost up to 10.11.15/10.11.16/11.5.4/11.6.1/11.6.x. It has been declared as problematic. Affected by this vulnerability is an unknown code block of the component Setting Handler. The manipulation with an unknown input leads to a authorization vulnerability. The CWE definition for the vulnerability is CWE-862. The product does not perform an authorization check when an actor attempts to access a resource or perform an action. As an impact it is known to affect integrity. The summary by CVE is:

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

The weakness was disclosed by 0x7oda7123. It is possible to read the advisory at mattermost.com. This vulnerability is known as CVE-2026-6689 since 04/20/2026. The exploitation appears to be easy. The attack can be launched remotely. The technical details are unknown and an exploit is not publicly available.

Upgrading to version 10.11.16, 10.11.17, 11.5.5, 11.6.2 or 11.7.0 eliminates this vulnerability.

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

Type

Name

Version

License

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 4.3
VulDB Meta Temp Score: 4.2

VulDB Base Score: 4.3
VulDB Temp Score: 4.1
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 4.3
CNA Vector (Mattermost): 🔒

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Authorization
CWE: CWE-862 / CWE-863 / CWE-285
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Mattermost 10.11.16/10.11.17/11.5.5/11.6.2/11.7.0

Timelineinfo

04/20/2026 CVE reserved
06/12/2026 +53 days Advisory disclosed
06/12/2026 +0 days VulDB entry created
06/12/2026 +0 days VulDB entry last update

Sourcesinfo

Advisory: mattermost.com
Researcher: 0x7oda7123
Status: Confirmed

CVE: CVE-2026-6689 (🔒)
GCVE (CVE): GCVE-0-2026-6689
GCVE (VulDB): GCVE-100-370627

Entryinfo

Created: 06/12/2026 19:29
Changes: 06/12/2026 19:29 (64)
Complete: 🔍
Cache ID: 216::103

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