CVE-2026-19541: 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) · Low privileges required · No user interaction required

What an attacker can do

The source says mattermost versions 11.9.x <= 11.9.1, 11.8.x <= 11.8.5, 11.7.x <= 11.7.10, 11.10.x <= 11.10.1 fail to require re-entry of the stored client secret when validating an outgoing OAuth connection, which allows an authenticated user with permission to manage outgoing OAuth connections to obtain the secret via pointing the token URL at an attacker-controlled endpoint and triggering validation. Vendor/CNA’s CVSS 3.1 assessment (base score 6.5/10) rates confidentiality impact as high; integrity and availability impact as none.