CVE-2026-19600: Mattermost 11.9.0 through 11.9.1, 11.8.0 through 11.8.5, 11.7.0 through 11.7.10, 11.10.0 through 11.10.1

Affected technology

Mattermost · 11.9.0 through 11.9.1, 11.8.0 through 11.8.5, 11.7.0 through 11.7.10, 11.10.0 through 11.10.1
Mattermost

Description’s affected range: versions 11.9.x <= 11.9.1

Component: Not specified by the source

Attack conditions (Vendor/CNA, CVSS 3.1): Network (remote) · High privileges required · User interaction required

What an attacker can do

An attacker with access to server logs can obtain valid session tokens or OAuth access tokens and impersonate authenticated users via the debug-level Mattermost server log. Vendor/CNA’s CVSS 3.1 assessment (base score 4.5/10) rates confidentiality impact as high; integrity and availability impact as none.