CVE-2026-21388
low-risk
Published 2026-04-09
Mattermost Plugins versions <=2.3.1 fail to limit the request body size on the {{/lifecycle}} webhook endpoint which allows an authenticated attacker to cause memory exhaustion and denial of service via sending an oversized JSON payload. Mattermost Advisory ID: MMSA-2026-00610
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
?
Patch status unknown
Check vendor advisories for fix availability and mitigation guidance
3
CVSS 3.7/10
Low
NETWORK
/ HIGH complexity
References (1)
18
/ 100
low-risk
Severity
13/34 · Low
Exploitability
0/34 · Minimal
Exposure
5/34 · Minimal