CVE-2026-4646

MEDIUM

Insufficient input validation in GitHub plugin API causes denial of service

Title source: cna
STIX 2.1

Description

Mattermost versions 11.6.x <= 11.6.0, 11.5.x <= 11.5.3, 11.4.x <= 11.4.4, 10.11.x <= 10.11.14 fail to validate user-supplied input in API request handlers which allows an authenticated attacker to crash the plugin process via a crafted HTTP request to the PR details endpoint.. Mattermost Advisory ID: MMSA-2026-00638

References (1)

Core 1
Core References
Vendor Advisory vendor-advisory
MMSA-2026-00638
https://mattermost.com/security-updates

Scores

CVSS v3 4.3
EPSS 0.0007
EPSS Percentile 22.2%
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L

CISA SSVC

Vulnrichment
Exploitation none
Automatable no
Technical Impact partial

Details

CWE
CWE-1287
Status published
Products (9)
Mattermost/Mattermost 10.11.0 - 10.11.14
Mattermost/Mattermost 10.11.15
Mattermost/Mattermost 11.4.0 - 11.4.4
Mattermost/Mattermost 11.4.5
Mattermost/Mattermost 11.5.0 - 11.5.3
Mattermost/Mattermost 11.5.4
Mattermost/Mattermost 11.6.0
Mattermost/Mattermost 11.6.1
Mattermost/Mattermost 11.7.0
Published May 22, 2026
Tracked Since May 22, 2026