Mattermost versions 11.3.x <= 11.3.0, 11.2.x <= 11.2.2, 10.11.x <= 10.11.10 Mattermost fails to limit the size of responses from integration action endpoints, which allows an authenticated attacker to cause server memory exhaustion and denial of service via a malicious integration server that returns an arbitrarily large response when a user clicks an interactive message button.. Mattermost Advisory ID: MMSA-2026-00571

Project Subscriptions

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Advisories

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Fixes

Solution

Update Mattermost to versions 11.4.0, 11.3.1, 11.2.3, 10.11.11 or higher.


Workaround

No workaround given by the vendor.

References
History

Mon, 16 Mar 2026 14:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

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


Mon, 16 Mar 2026 11:30:00 +0000

Type Values Removed Values Added
Description Mattermost versions 11.3.x <= 11.3.0, 11.2.x <= 11.2.2, 10.11.x <= 10.11.10 Mattermost fails to limit the size of responses from integration action endpoints, which allows an authenticated attacker to cause server memory exhaustion and denial of service via a malicious integration server that returns an arbitrarily large response when a user clicks an interactive message button.. Mattermost Advisory ID: MMSA-2026-00571
Title Denial of Service via Unbounded Memory Allocation in Integration Actions
Weaknesses CWE-789
References
Metrics cvssV3_1

{'score': 5.3, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:H'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: Mattermost

Published:

Updated: 2026-03-16T13:49:58.650Z

Reserved: 2026-02-13T11:02:52.828Z

Link: CVE-2026-2456

cve-icon Vulnrichment

Updated: 2026-03-16T13:44:23.990Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-03-16T14:19:29.190

Modified: 2026-03-16T14:53:07.390

Link: CVE-2026-2456

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses