{
    "id": "CVE-2021-27889",
    "published": "2021-03-15 17:15:22",
    "last_modified": "2026-06-17 03:45:33",
    "cvss_score": "6.1",
    "cvss_severity": "MEDIUM",
    "cvss_version": "3.1",
    "cvss_vector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N",
    "cwe": "CWE-79",
    "description": "Cross-site Scripting (XSS) vulnerability in MyBB before 1.8.26 via Nested Auto URL when parsing messages.",
    "epss_score": "0.05072",
    "epss_percentile": "0.92070",
    "kev": 0,
    "kev_due": null,
    "has_exploit": 1,
    "updated_at": "2026-10-02 18:17:29",
    "priority": {
        "rank": 2,
        "label": "Patch early",
        "why": "A public exploit exists."
    },
    "products": [
        {
            "vendor": "mybb",
            "product": "mybb"
        }
    ],
    "kev_detail": null,
    "exploits": [
        {
            "source": "exploit-db",
            "ref_id": "49696",
            "title": "MyBB 1.8.25 - Chained Remote Command Execution",
            "date": "2021-03-22",
            "url": "https://www.exploit-db.com/exploits/49696"
        }
    ],
    "refs_list": [
        "http://packetstormsecurity.com/files/161908/MyBB-1.8.25-Remote-Command-Execution.html",
        "https://blog.sonarsource.com/mybb-remote-code-execution-chain",
        "https://github.com/mybb/mybb/security/advisories/GHSA-xhj7-3349-mqcm",
        "http://packetstormsecurity.com/files/161908/MyBB-1.8.25-Remote-Command-Execution.html",
        "https://blog.sonarsource.com/mybb-remote-code-execution-chain",
        "https://github.com/mybb/mybb/security/advisories/GHSA-xhj7-3349-mqcm"
    ]
}