CVE-2026-1628 MEDIUM

CVE-2026-1628: Mattermost allows external websites to open within the app, exposing preload functionality to non-trusted sites.

Vendor Mattermost
Product Mattermost
Weakness CWE-829 · Inclusion from untrusted sphere
Published March 2, 2026
Last update March 2, 2026
View on NVD All CVEs

CVSS base score

4.6/10
Attack vector Network
Attack complexity Low
Privileges required Low
User interaction Required
Confidentiality Low
Integrity Low

CVSS vector

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

What the vulnerability does

01Description

Mattermost Desktop App versions <=5.13.3 fail to attach listeners restricting navigation to external sites within the Mattermost app which allows a malicious server to expose preload script functionality to untrusted servers via having a user open an external link in their Mattermost server. Mattermost Advisory ID: MMSA-2026-00596

Key dates

02Disclosure timeline

March 2, 2026 CVE published
March 2, 2026 Record updated