CVE-2026-3590 MEDIUM

CVE-2026-3590: Race Condition in Guest Magic Link Authentication Allows Token Reuse

Vendor Mattermost
Product Mattermost
Weakness CWE-367
Published April 15, 2026
Last update April 15, 2026
View on NVD All CVEs

CVSS base score

6.5/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Confidentiality Low
Integrity Low

CVSS vector

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

What the vulnerability does

01Description

Mattermost versions 10.11.x <= 10.11.12, 11.5.x <= 11.5.0, 11.4.x <= 11.4.2, 11.3.x <= 11.3.2 fail to enforce atomic single-use consumption of guest magic link tokens, which allows an attacker with access to a valid magic link to establish multiple independent authenticated sessions via concurrent requests.. Mattermost Advisory ID: MMSA-2026-00624

Key dates

02Disclosure timeline

April 15, 2026 CVE published
April 15, 2026 Record updated