lichess.org has an Unsanitized Stream Title Injection on /streamer_CVE-2026-35208

{
    "lastseen": "",
    "description": "lichess.org is the forever free, adless and open source chess server. Any approved streamer can inject arbitrary HTML into /streamer and the homepage \u201cLive streams\u201d widget by placing markup in their Twitch/YouTube stream title. CSP is present and blocks inline script execution, but the issue is still a server-side HTML injection sink. To trigger this, a Lichess account only needs to satisfy the normal streamer requirements and get approved. Per Streamer.canApply, that means an account older than 2 days with at least 15 games, or a verified/titled account. After moderator approval, once the streamer goes live, Lichess pulls the platform title and renders it into the UI as-is. No extra privileges are needed beyond a normal approved streamer profile. This vulnerability is fixed with commit 0d5002696ae705e1888bf77de107c73de57bb1b3.",
    "published": "2026-04-06T20:06:25.821Z",
    "modified": "2026-04-07T15:09:55.304Z",
    "type": "cve",
    "title": "lichess.org has an Unsanitized Stream Title Injection on /streamer",
    "source": "GitHub_M",
    "references": "https://github.com/lichess-org/lila/security/advisories/GHSA-v7gh-939r-pfjq\nhttps://github.com/lichess-org/lila/commit/0d5002696ae705e1888bf77de107c73de57bb1b3\nhttps://vimeo.com/1175908262",
    "id": "CVE-2026-35208",
    "bulletinFamily": "",
    "cwe": [
        "CWE-79",
        "CWE-116"
    ],
    "cvelist": null,
    "sourceData": "lichess-org lila < 0d5002696ae705e1888bf77de107c73de57bb1b3",
    "sourceHref": "",
    "cvss": {
        "score": 5.3,
        "severity": "MEDIUM",
        "vector": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N",
        "version": "4.0"
    },
    "cvss2": [],
    "cvss3": {
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        "vectorString": "",
        "baseScore": 0,
        "baseSeverity": "",
        "attackVector": "",
        "attackComplexity": "",
        "privilegesRequired": "",
        "userInteraction": "",
        "scope": "",
        "confidentialityImpact": "",
        "integrityImpact": "",
        "availabilityImpact": "",
        "cvssV3": {
            "version": "",
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        }
    },
    "href": "",
    "category_name": "CVE",
    "post_link": "",
    "product": "lila",
    "version": "< 0d5002696ae705e1888bf77de107c73de57bb1b3",
    "vendor": "lichess-org",
    "ai_description": "",
    "ai_severity": "",
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    "ai_score": 0
}