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

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

Problem type

CWE-770: Allocation of Resources Without Limits or Throttling

Affected products

Mattermost

Mattermost

<= 2.3.1 - AFFECTED

2.3.2.0 - UNAFFECTED

References

MMSA-2026-00610

https://mattermost.com/security-updates

vendor-advisory

JSON source

https://cveawg.mitre.org/api/cve/CVE-2026-21388

Click to expand

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    "dateUpdated": "2026-04-09T11:44:54.614Z",
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            "privilegesRequired": "NONE",
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