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

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Advisories

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Fixes

Solution

Update Mattermost Desktop App to versions 5.13.4.0 or higher.


Workaround

No workaround given by the vendor.

References
History

Thu, 05 Mar 2026 16:15:00 +0000

Type Values Removed Values Added
First Time appeared Mattermost mattermost Desktop
CPEs cpe:2.3:a:mattermost:mattermost_desktop:*:*:*:*:*:*:*:*
Vendors & Products Mattermost mattermost Desktop

Wed, 04 Mar 2026 11:00:00 +0000

Type Values Removed Values Added
First Time appeared Mattermost
Mattermost mattermost
Vendors & Products Mattermost
Mattermost mattermost

Mon, 02 Mar 2026 15:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Mon, 02 Mar 2026 13:45:00 +0000

Type Values Removed Values Added
Description 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
Title Mattermost allows external websites to open within the app, exposing preload functionality to non-trusted sites.
Weaknesses CWE-829
References
Metrics cvssV3_1

{'score': 4.6, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: Mattermost

Published:

Updated: 2026-03-02T14:58:30.546Z

Reserved: 2026-01-29T15:14:51.993Z

Link: CVE-2026-1628

cve-icon Vulnrichment

Updated: 2026-03-02T14:58:22.983Z

cve-icon NVD

Status : Analyzed

Published: 2026-03-02T14:16:23.223

Modified: 2026-03-05T16:07:40.963

Link: CVE-2026-1628

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-03-03T08:45:11Z

Weaknesses