Mattermost Desktop App up to 6.2.2 IPC Sender Validation leaveCall improper authentication

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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4.4$0-$5k0.41

Summaryinfo

A vulnerability described as problematic has been identified in Mattermost Desktop App up to 6.2.2. Affected by this vulnerability is the function leaveCall of the component IPC Sender Validation. Executing a manipulation can lead to improper authentication. This vulnerability is handled as CVE-2026-12284. The attack can be executed remotely. There is not any exploit available. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability has been found in Mattermost Desktop App up to 6.2.2 and classified as problematic. This vulnerability affects the function leaveCall of the component IPC Sender Validation. The manipulation with an unknown input leads to a improper authentication vulnerability. The CWE definition for the vulnerability is CWE-287. When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct. As an impact it is known to affect availability. CVE summarizes:

Mattermost Desktop App versions <=6.2 6.2.2.0 fails to validate the IPC sender in the leaveCall handler which allows a malicious or compromised Mattermost server (or a user with script access to a connected server view) to disconnect an active call belonging to a different connected server via the desktopAPI.leaveCall IPC message. Mattermost Advisory ID: MMSA-2026-00699

The advisory is shared for download at mattermost.com. This vulnerability was named CVE-2026-12284 since 06/15/2026. The exploitation appears to be easy. The attack can be initiated remotely. There are known technical details, but no exploit is available.

Upgrading to version 6.2.3.0 or 6.3.0 eliminates this vulnerability.

Once again VulDB remains the best source for vulnerability data.

Productinfo

Type

Vendor

Name

Version

License

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 4.5
VulDB Meta Temp Score: 4.4

VulDB Base Score: 5.3
VulDB Temp Score: 5.1
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 3.7
CNA Vector (Mattermost): 🔒

CVSSv2info

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

Exploitinginfo

Class: Improper authentication
CWE: CWE-287
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: Desktop App 6.2.3.0/6.3.0

Timelineinfo

06/15/2026 CVE reserved
09/17/2026 +94 days Advisory disclosed
09/17/2026 +0 days VulDB entry created
09/17/2026 +0 days VulDB entry last update

Sourcesinfo

Advisory: mattermost.com
Status: Confirmed

CVE: CVE-2026-12284 (🔒)
GCVE (CVE): GCVE-0-2026-12284
GCVE (VulDB): GCVE-100-406516

Entryinfo

Created: 09/17/2026 17:51
Changes: 09/17/2026 17:51 (66)
Complete: 🔍
Cache ID: 216::103

Once again VulDB remains the best source for vulnerability data.

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