Is CVE-2026-2456 actively exploited?

No active exploitation of CVE-2026-2456 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2026-2456 be exploited remotely?

Yes. CVE-2026-2456 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2026-2456?

CVE-2026-2456 has a CVSS score of 5.7 (MEDIUM).

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MEDIUM

CVE-2026-2456

CWE-789Published: March 16, 2026· Updated: Mar 18, 2026

5.7

CVSS v3.1

EPSS:0.03%probability of exploitation in 30 daysPercentile:9.5th

Official 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

NVD Source

Technical Analysis

CVE-2026-2456 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

Exploitation requires low privileges, which limits the exposure to scenarios where an attacker has already gained initial access.

A successful exploit results in availability disruption (denial of service), with a CVSS base score of 5.7.