CVE-2026-9602

EUVD-2026-45156
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
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
MattermostCNA
6.5 MEDIUM
NETWORK
LOW
LOW
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Base Score
CVSS 3.x
EPSS Score
Percentile: 35.02%
Affected Products (NVD)
VendorProductVersion
mattermostmattermost_desktop
5.6.13 ≤
𝑥
< 5.13.7
mattermostmattermost_desktop
6.0.2 ≤
𝑥
< 6.2.1
mattermostmattermost_desktop
6.2.1 <
𝑥
< 6.3
𝑥
= Vulnerable software versions
Early Detection
Affected products identified ahead of NVD analysis through intelligence sources.
VendorProductVersionSource
mattermostmattermost
𝑥
≤ 6.0.2
CNA
mattermostmattermost
𝑥
≤ 5.6.13
CNA
Common Weakness Enumeration
References
https://mattermost.com/security-updates