Mattermost up to 11.6.x Role Patch API authorization

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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5.6$0-$5k4.10

Summaryinfo

A vulnerability has been found in Mattermost up to 10.11.15/10.11.16/11.5.4/11.6.1/11.6.x and classified as problematic. This affects an unknown function of the component Role Patch API. Performing a manipulation results in authorization. This vulnerability was named CVE-2026-6739. The attack may be initiated remotely. There is no available exploit. The affected component should be upgraded.

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 classified as problematic. This affects an unknown part of the component Role Patch API. The manipulation with an unknown input leads to a authorization vulnerability. CWE is classifying the issue as CWE-863. The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check. This allows attackers to bypass intended access restrictions. This is going to have an impact on confidentiality, integrity, and availability. 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 require system-level permission when patching protected default system roles, which allows authenticated users with delegated user-management permissions to escalate privileges by altering built-in role permissions via the role patch API.. Mattermost Advisory ID: MMSA-2026-00656

The weakness was presented by NeganSpl01t. The advisory is shared at mattermost.com. This vulnerability is uniquely identified as CVE-2026-6739 since 04/21/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. Additional levels of successful authentication are necessary for exploitation. Neither technical details nor an exploit are publicly available.

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

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Type

Name

Version

License

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.7
VulDB Meta Temp Score: 5.6

VulDB Base Score: 4.7
VulDB Temp Score: 4.5
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 6.7
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-863 / CWE-285 / CWE-266
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

04/21/2026 CVE reserved
06/12/2026 +52 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: NeganSpl01t
Status: Confirmed

CVE: CVE-2026-6739 (🔒)
GCVE (CVE): GCVE-0-2026-6739
GCVE (VulDB): GCVE-100-370653

Entryinfo

Created: 06/12/2026 19:35
Changes: 06/12/2026 19:35 (64)
Complete: 🔍
Cache ID: 216::103

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

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