Rocket.Chat: Missing URL protocol sanitization in ImageElement allows javascript: URLs in markdown images_CVE-2026-47733

{
    "lastseen": "",
    "description": "Rocket.Chat is an open-source, secure, fully customizable communications platform. Prior to 8.5.0, the ImageElement component in packages/gazzodown renders user-controlled src values directly into <a href> and <img src> attributes without protocol sanitization. Unlike the analogous LinkSpan component \u2014 which uses sanitizeUrl to block javascript:, data:, and vbscript: protocols \u2014 ImageElement passes the raw URL through unchanged. An authenticated user can post a markdown image with a javascript: URL that, if clicked on an older browser, would execute arbitrary JavaScript in the viewer's session. This vulnerability is fixed in 8.5.0.",
    "published": "2026-06-24T20:51:29.245Z",
    "modified": "2026-06-24T20:51:29.245Z",
    "type": "cve",
    "title": "Rocket.Chat: Missing URL protocol sanitization in ImageElement allows javascript: URLs in markdown images",
    "source": "GitHub_M",
    "references": "https://github.com/RocketChat/Rocket.Chat/security/advisories/GHSA-vvrf-fq54-q4pr",
    "id": "CVE-2026-47733",
    "bulletinFamily": "",
    "cwe": [
        "CWE-79"
    ],
    "cvelist": null,
    "sourceData": "RocketChat Rocket.Chat < 8.5.0",
    "sourceHref": "",
    "cvss": {
        "score": 4.4,
        "severity": "MEDIUM",
        "vector": "CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:L/I:L/A:N",
        "version": "3.1"
    },
    "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": "Rocket.Chat",
    "version": "< 8.5.0",
    "vendor": "RocketChat",
    "ai_description": "",
    "ai_severity": "",
    "ai_vendor": "",
    "ai_product": "",
    "ai_version": "",
    "ai_score": 0
}