CVE-2026-21388 — Unbounded Request Body Read in MS Teams Plugin {{/lifecycle}} Webhook Endpoint

CVE-2026-21388

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

Description (CNA)

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

Affected (CNA)

Vendor / product	Versions
Mattermost / Mattermost	affected 0 through 2.3.1; unaffected 2.3.2.0

CWE

CWE-770

References

https://mattermost.com/security-updates

ADP enrichment

CISA-ADP

No English description supplied.

No references supplied.