5.3
MEDIUM CVSS 3.1
CVE-2026-2456
Denial of Service via Unbounded Memory Allocation in Integration Actions
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

INFO

Published Date :

March 16, 2026, 11:06 a.m.

Last Modified :

March 16, 2026, 11:06 a.m.

Remotely Exploit :

Yes !

Source :

Mattermost
Affected Products

The following products are affected by CVE-2026-2456 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 MEDIUM 9302f53e-dde5-4bf3-b2f2-a83f91ac0eee
Solution
Update Mattermost to patch the response size limit vulnerability. This prevents DoS via large integration responses.
  • Update Mattermost to a non-vulnerable version.
  • Apply security patches provided by the vendor.
  • Configure integration response size limits.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-2456 vulnerability anywhere in the article.

EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.