CVE-2026-4646 MEDIUM

CVE-2026-4646: Insufficient input validation in GitHub plugin API causes denial of service

Vendor Mattermost
Product Mattermost
Weakness CWE-1287
Published May 22, 2026
Last update May 22, 2026
View on NVD All CVEs

CVSS base score

4.3/10
Attack vector Network
Attack complexity Low
Privileges required Low
User interaction None
Confidentiality None
Integrity None

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L

What the vulnerability does

01Description

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

Key dates

02Disclosure timeline

May 22, 2026 CVE published
May 22, 2026 Record updated