CVE-2026-19621

Published: Oct 16, 2026Modified: Oct 16, 2026

6.5

Vector

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

Exploitability: 2.8 / Impact: 3.6

Source: responsibledisclosure@mattermost.com (Secondary)

Description

Mattermost versions 11.10.x <= 11.10.0, 11.7.x <= 11.7.9, 11.9.x <= 11.9.1, 11.8.x <= 11.8.5 fail to strip action integration secrets from post payloads before broadcasting post-deletion web socket events and returning thread API responses, which allows an authenticated channel member to obtain server-side webhook URLs and authentication context from interactive-message posts via the post_deleted websocket event or the threads REST API.. Mattermost Advisory ID: MMSA-2026-00766

Related CWEs

CWE-200

Exposure of Sensitive Information to an Unauthorized Actor

The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information.

References (1)

https://mattermost.com/security-updates

Source: responsibledisclosure@mattermost.com

Timeline

No history available yet.