Mattermost up to 10.11.12/11.4.x Conntexted Workspaces Feature authorization

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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2.7$0-$5k0.00

Summaryinfo

A vulnerability classified as problematic has been found in Mattermost up to 10.11.12/11.4.x. This issue affects some unknown processing of the component Conntexted Workspaces Feature. The manipulation leads to authorization. This vulnerability is listed as CVE-2026-27769. The attack may be initiated remotely. There is no available exploit. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability was found in Mattermost up to 10.11.12/11.4.x. It has been rated as problematic. This issue affects some unknown processing of the component Conntexted Workspaces Feature. The manipulation with an unknown input leads to a authorization vulnerability. Using CWE to declare the problem leads to CWE-862. The product does not perform an authorization check when an actor attempts to access a resource or perform an action. Impacted is integrity. The summary by CVE is:

Mattermost versions 10.11.x <= 10.11.12 fail to validate whether users were correctly owned by the correct Connected Workspace which allows a malicious remote server connected using the Conntexted Workspaces feature to change the displayed status of local users via the Connected Workspaces API.. Mattermost Advisory ID: MMSA-2026-00603

The weakness was presented by daw10. The advisory is shared at mattermost.com. The identification of this vulnerability is CVE-2026-27769 since 03/16/2026. The exploitation is known to be easy. The attack may be initiated remotely. Additional levels of successful authentication are necessary for exploitation. Neither technical details nor an exploit are publicly available.

Upgrading to version 10.11.13 or 11.5.0 eliminates this vulnerability.

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Type

Name

Version

License

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 2.7
VulDB Meta Temp Score: 2.7

VulDB Base Score: 2.7
VulDB Temp Score: 2.6
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 2.7
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-862 / CWE-863 / CWE-285
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

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 10.11.13/11.5.0

Timelineinfo

03/16/2026 CVE reserved
04/15/2026 +29 days Advisory disclosed
04/15/2026 +0 days VulDB entry created
04/15/2026 +0 days VulDB entry last update

Sourcesinfo

Advisory: mattermost.com
Researcher: daw10
Status: Confirmed

CVE: CVE-2026-27769 (🔒)
GCVE (CVE): GCVE-0-2026-27769
GCVE (VulDB): GCVE-100-357713

Entryinfo

Created: 04/15/2026 14:02
Changes: 04/15/2026 14:02 (64)
Complete: 🔍
Cache ID: 216::103

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Discussion

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