### [CVE-2017-18889](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-18889)
![](https://img.shields.io/static/v1?label=Product&message=n%2Fa&color=blue)
![](https://img.shields.io/static/v1?label=Version&message=n%2Fa&color=blue)
![](https://img.shields.io/static/v1?label=Vulnerability&message=n%2Fa&color=brighgreen)

### Description

An issue was discovered in Mattermost Server before 4.3.0, 4.2.1, and 4.1.2. An attacker could create fictive system-message posts via webhooks and slash commands, in the v3 or v4 REST API.

### POC

#### Reference
- https://mattermost.com/security-updates/

#### Github
No PoCs found on GitHub currently.