GHSA-x274-8qfc-hrgf
Mattermost MS Teams plugin doesn't limit the request body size on the /lifecycle webhook endpoint
Packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| Go | github.com/mattermost/mattermost-plugin-msteams | < 1.15.1-0.20260213190728-6fe4d295592e | 1.15.1-0.20260213190728-6fe4d295592e |
Details
As written in the advisory (Markdown source, shown as plain text).
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.
References
External links from the advisory. They lead to third-party sites.
- https://nvd.nist.gov/vuln/detail/CVE-2026-21388
- https://github.com/mattermost/mattermost-plugin-msteams/commit/6fe4d295592ecc8767d67e69286cbeec01be3210
- https://github.com/mattermost/mattermost-plugin-msteams
- https://github.com/mattermost/mattermost-plugin-msteams/releases/tag/v2.3.2
- https://mattermost.com/security-updates