CVE-2026-21388lowCWE-770

CVE-2026-21388: low-severity vulnerability in Mattermost

Unbounded Request Body Read in MS Teams Plugin {{/lifecycle}} Webhook Endpoint

Published

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8Vexday Risk Score

No sign of exploitation. No public exploitation artifact known so far.

ssvc Trackcvss 3.7epss 0.3%
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
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L
Affected products
Mattermost · Mattermost
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