CVE-2026-2578 MEDIUM

CVE-2026-2578: Information Disclosure via WebSocket Event When Deleting Unrevealed Burn on Read Posts

Vendor Mattermost
Product Mattermost
Weakness CWE-201
Published March 16, 2026
Last update March 16, 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 Low
Integrity None

CVSS vector

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

What the vulnerability does

01Description

Mattermost versions 11.3.x <= 11.3.0 fail to preserve the redacted state of burn-on-read posts during deletion which allows channel members to access unrevealed burn-on-read message contents via the WebSocket post deletion event.. Mattermost Advisory ID: MMSA-2026-00579

Key dates

02Disclosure timeline

March 16, 2026 CVE published
March 16, 2026 Record updated