An issue was discovered in Mattermost Server before 4.0.0, 3.10.2, and 3.9.2, when Single Sign-On OAuth2 is used. An attacker could claim somebody else's account.
{
"github_reviewed": true,
"github_reviewed_at": "2026-02-06T22:42:23Z",
"severity": "HIGH",
"nvd_published_at": "2020-06-19T20:15:00Z",
"cwe_ids": [
"CWE-613"
]
}