PT-2026-25678 · Mattermost · Mattermost

Published

2026-02-13

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Updated

2026-03-27

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CVE-2026-2456

CVSS v2.0

6.8

Medium

VectorAV:N/AC:L/Au:S/C:N/I:N/A:C
Name of the Vulnerable Software and Affected Versions Mattermost versions 10.11.0 through 10.11.10 Mattermost versions 11.2.0 through 11.2.2 Mattermost versions 11.3.0 through 11.3.0
Description Mattermost does not limit the size of responses from integration action endpoints. This allows an authenticated attacker to cause server memory exhaustion and a denial of service. The attack involves a malicious integration server returning an arbitrarily large response when a user clicks an interactive message button. The affected API endpoint is the integration action endpoint. The response parameter from the integration server is the vulnerable component.
Recommendations Mattermost versions 10.11.0 through 10.11.10 should be updated. Mattermost versions 11.2.0 through 11.2.2 should be updated. Mattermost version 11.3.0 should be updated.

Fix

DoS

Resource Exhaustion

Weakness Enumeration

CWE-400CWE-789

Related Identifiers

BDU:2026-06565
CVE-2026-2456
GHSA-34G8-9FPP-46CH
GO-2026-4726
SUSE-SU-2026:1135-1

Affected Products

Mattermost