OpenProject: Stored XSS on openproject.example.com through /api/v3/projects/{project}/work_packages via POST parameter “description”_CVE-2026-52781

{
    "lastseen": "",
    "description": "OpenProject is open-source, web-based project management software. Prior to 17.3.3 and 17.4.1, the HTML sanitizer grants <macro> elements unrestricted data-* attributes via :data wildcard. An attacker injects data-controller=\"poll-for-changes\" into a work package description, causing Stimulus.js to mount a controller that fetches an attacker-uploaded attachment and passes it to renderStreamMessage(). This executes arbitrary Turbo Stream actions \u2014 including redirect_to \u2014 in every victim's authenticated browser session, redirecting them to an attacker-controlled server. This vulnerability is fixed in 17.3.3 and 17.4.1.",
    "published": "2026-06-26T19:00:10.717Z",
    "modified": "2026-06-26T19:00:10.717Z",
    "type": "cve",
    "title": "OpenProject: Stored XSS on openproject.example.com through /api/v3/projects/{project}/work_packages via POST parameter \"description\"",
    "source": "GitHub_M",
    "references": "https://github.com/opf/openproject/security/advisories/GHSA-q33w-f822-hg8x",
    "id": "CVE-2026-52781",
    "bulletinFamily": "",
    "cwe": [
        "CWE-79"
    ],
    "cvelist": null,
    "sourceData": "opf openproject < 17.3.3\nopf openproject >= 17.4.0, < 17.4.1",
    "sourceHref": "",
    "cvss": {
        "score": 6.4,
        "severity": "MEDIUM",
        "vector": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/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": "openproject",
    "version": "< 17.3.3",
    "vendor": "opf",
    "ai_description": "",
    "ai_severity": "",
    "ai_vendor": "",
    "ai_product": "",
    "ai_version": "",
    "ai_score": 0
}