Mattermost Desktop App up to 5.6.13/6.0.2/6.2.x Payload Validator out-of-bounds write

CVSS Meta Temp Score
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CTI Interest Score
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5.1$0-$5k3.03

Summaryinfo

A vulnerability classified as problematic was found in Mattermost Desktop App up to 5.6.13/6.0.2/6.2.x. This vulnerability affects unknown code of the component Payload Validator. Such manipulation leads to out-of-bounds write. This vulnerability is listed as CVE-2026-9602. The attack may be performed from remote. There is no available exploit.

Detailsinfo

A vulnerability was found in Mattermost Desktop App up to 5.6.13/6.0.2/6.2.x and classified as problematic. Affected by this issue is an unknown function of the component Payload Validator. The manipulation with an unknown input leads to a out-of-bounds write vulnerability. Using CWE to declare the problem leads to CWE-787. The product writes data past the end, or before the beginning, of the intended buffer. Impacted is availability. CVE summarizes:

Mattermost Desktop App versions <=6.2 6.0.2 5.6.13.0 fail to validate payloads sent from the Mattermost Web App to the Desktop App which allows a malicious server owner to crash the Mattermost Desktop App via changing the payload of a method to a malformed one. Mattermost Advisory ID: MMSA-2026-00678

The advisory is available at mattermost.com. This vulnerability is handled as CVE-2026-9602 since 05/26/2026. The exploitation is known to be easy. The attack may be launched remotely. No form of authentication is required for exploitation. The technical details are unknown and an exploit is not available.

Upgrading to version 5.13.7.0, 6.2.1.0 or 6.3.0 eliminates this vulnerability.

If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

Type

Vendor

Name

Version

License

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.3
VulDB Meta Temp Score: 5.1

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

CVSSv2info

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

Exploitinginfo

Class: Out-of-bounds write
CWE: CWE-787 / CWE-119
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: no mitigation known
Status: 🔍

0-Day Time: 🔒

Upgrade: Desktop App 5.13.7.0/6.2.1.0/6.3.0

Timelineinfo

05/26/2026 CVE reserved
07/17/2026 +52 days Advisory disclosed
07/17/2026 +0 days VulDB entry created
07/17/2026 +0 days VulDB entry last update

Sourcesinfo

Advisory: mattermost.com
Status: Confirmed

CVE: CVE-2026-9602 (🔒)
GCVE (CVE): GCVE-0-2026-9602
GCVE (VulDB): GCVE-100-379778

Entryinfo

Created: 07/17/2026 12:36
Changes: 07/17/2026 12:36 (54)
Complete: 🔍
Cache ID: 216::103

If you want to get best quality of vulnerability data, you may have to visit VulDB.

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