CVE-2026-2456

low-risk
Published 2026-03-16

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

Do I need to act?

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0.04% chance of exploitation
EPSS score — low exploit probability
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Not on CISA KEV list
No confirmed active exploitation reported to CISA
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Patch status unknown
Check vendor advisories for fix availability and mitigation guidance
5
CVSS 5.3/10 Medium
NETWORK / HIGH complexity

Affected Products (1)

Affected Vendors

Mattermost

References (1)

Vendor Advisory https://mattermost.com/security-updates
22
/ 100
low-risk
Severity 17/34 · Moderate
Exploitability 0/34 · Minimal
Exposure 5/34 · Minimal