Mattermost versions 11.9.x <= 11.9.0, 11.8.x <= 11.8.4, 11.7.x <= 11.7.7, 10.11.x <= 10.11.22 fail to limit the amount of memory allocated when decoding uploaded image files which allows an authenticated user to cause excessive server memory consumption and potential denial of service via uploading a specially crafted image as a profile picture, channel file attachment, team icon, or custom brand image. Mattermost Advisory ID: MMSA-2026-00719
Advisories

No advisories yet.

Fixes

Solution

Update Mattermost to versions 11.10.0, 11.9.1, 11.8.5, 11.7.8, 10.11.23 or higher.


Workaround

No workaround given by the vendor.

References
History

Mon, 14 Sep 2026 12:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

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


Mon, 14 Sep 2026 11:45:00 +0000

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

Mon, 14 Sep 2026 10:45:00 +0000

Type Values Removed Values Added
Description Mattermost versions 11.9.x <= 11.9.0, 11.8.x <= 11.8.4, 11.7.x <= 11.7.7, 10.11.x <= 10.11.22 fail to limit the amount of memory allocated when decoding uploaded image files which allows an authenticated user to cause excessive server memory consumption and potential denial of service via uploading a specially crafted image as a profile picture, channel file attachment, team icon, or custom brand image. Mattermost Advisory ID: MMSA-2026-00719
Title Uploading a crafted image causes excessive memory allocation in the Mattermost Server
Weaknesses CWE-409
References
Metrics cvssV3_1

{'score': 6.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: Mattermost

Published:

Updated: 2026-09-14T11:19:45.210Z

Reserved: 2026-07-15T10:53:51.646Z

Link: CVE-2026-15814

cve-icon Vulnrichment

Updated: 2026-09-14T11:13:35.352Z

cve-icon NVD

Status : Received

Published: 2026-09-14T11:17:03.697

Modified: 2026-09-14T12:17:38.347

Link: CVE-2026-15814

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-09-14T11:30:08Z

Weaknesses