Mattermost versions 11.4.x <= 11.4.0, 11.3.x <= 11.3.1, 11.2.x <= 11.2.3, 10.11.x <= 10.11.11 fail to prevent rendering of external SVGs on link embeds which allows unauthenticated users to crash the Mattermost webapp and desktop app via creating an issue or PR on GitHub.. Mattermost Advisory ID: MMSA-2026-00595

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Fixes

Solution

Update Mattermost to versions 11.5.0, 11.4.1, 11.3.2, 11.2.4, 10.11.12 or higher.


Workaround

No workaround given by the vendor.

References
History

Thu, 26 Mar 2026 19:00:00 +0000

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

Thu, 26 Mar 2026 18:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

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


Thu, 26 Mar 2026 12:00:00 +0000

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

Wed, 25 Mar 2026 16:45:00 +0000

Type Values Removed Values Added
Description Mattermost versions 11.4.x <= 11.4.0, 11.3.x <= 11.3.1, 11.2.x <= 11.2.3, 10.11.x <= 10.11.11 fail to prevent rendering of external SVGs on link embeds which allows unauthenticated users to crash the Mattermost webapp and desktop app via creating an issue or PR on GitHub.. Mattermost Advisory ID: MMSA-2026-00595
Title DoS via URL Previews Rendering Malicious SVGs
Weaknesses CWE-754
References
Metrics cvssV3_1

{'score': 4.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: Mattermost

Published:

Updated: 2026-03-26T17:11:21.474Z

Reserved: 2026-02-23T22:07:32.817Z

Link: CVE-2026-20719

cve-icon Vulnrichment

Updated: 2026-03-26T17:11:18.760Z

cve-icon NVD

Status : Analyzed

Published: 2026-03-25T17:16:30.307

Modified: 2026-03-26T18:54:18.977

Link: CVE-2026-20719

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-03-27T09:30:32Z

Weaknesses