league/commonmark has an embed extension allowed_domains bypass_CVE-2026-33347

{
    "lastseen": "",
    "description": "league/commonmark is a PHP Markdown parser. From version 2.3.0 to before version 2.8.2, the DomainFilteringAdapter in the Embed extension is vulnerable to an allowlist bypass due to a missing hostname boundary assertion in the domain-matching regex. An attacker-controlled domain like youtube.com.evil passes the allowlist check when youtube.com is an allowed domain. This issue has been patched in version 2.8.2.",
    "published": "2026-03-24T19:26:23.872Z",
    "modified": "2026-03-26T19:52:12.754Z",
    "type": "cve",
    "title": "league/commonmark has an embed extension allowed_domains bypass",
    "source": "GitHub_M",
    "references": "https://github.com/thephpleague/commonmark/security/advisories/GHSA-hh8v-hgvp-g3f5\nhttps://github.com/thephpleague/commonmark/commit/59fb075d2101740c337c7216e3f32b36c204218b\nhttps://github.com/thephpleague/commonmark/releases/tag/2.8.2",
    "id": "CVE-2026-33347",
    "bulletinFamily": "",
    "cwe": [
        "CWE-79",
        "CWE-185",
        "CWE-918"
    ],
    "cvelist": null,
    "sourceData": "thephpleague commonmark >= 2.3.0, < 2.8.2",
    "sourceHref": "",
    "cvss": {
        "score": 6.3,
        "severity": "MEDIUM",
        "vector": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:L/SI:L/SA:N",
        "version": "4.0"
    },
    "cvss2": [],
    "cvss3": {
        "version": "",
        "vectorString": "",
        "baseScore": 0,
        "baseSeverity": "",
        "attackVector": "",
        "attackComplexity": "",
        "privilegesRequired": "",
        "userInteraction": "",
        "scope": "",
        "confidentialityImpact": "",
        "integrityImpact": "",
        "availabilityImpact": "",
        "cvssV3": {
            "version": "",
            "vectorString": "",
            "baseScore": 0,
            "baseSeverity": "",
            "attackVector": "",
            "attackComplexity": "",
            "privilegesRequired": "",
            "userInteraction": "",
            "scope": "",
            "confidentialityImpact": "",
            "integrityImpact": "",
            "availabilityImpact": ""
        }
    },
    "href": "",
    "category_name": "CVE",
    "post_link": "",
    "product": "commonmark",
    "version": ">= 2.3.0, < 2.8.2",
    "vendor": "thephpleague",
    "ai_description": "",
    "ai_severity": "",
    "ai_vendor": "",
    "ai_product": "",
    "ai_version": "",
    "ai_score": 0
}