An issue was discovered in Mattermost Server before 4.0.0, 3.10.2, and 3.9.2. XSS could occur via a channel header.
{
"github_reviewed_at": "2026-02-06T22:44:36Z",
"github_reviewed": true,
"nvd_published_at": "2020-06-19T20:15:00Z",
"cwe_ids": [
"CWE-79"
],
"severity": "MODERATE"
}