CVE-2026-35208

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{"affected": [{"affectedData": [{"product": "lila", "vendor": "lichess-org", "versions": [{"status": "affected", "version": "< 0d5002696ae705e1888bf77de107c73de57bb1b3"}]}], "source": "security-advisories@github.com"}], "configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:a:lichess:lila:*:*:*:*:*:*:*:*", "matchCriteriaId": "A9D5C218-3446-4056-881F-89DBF44EA3C9", "versionEndExcluding": "2026-03-31", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "descriptions": [{"lang": "en", "value": "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."}, {"lang": "es", "value": "lichess.org es el servidor de ajedrez para siempre gratuito, sin anuncios y de c\u00f3digo abierto. Cualquier streamer aprobado puede inyectar HTML arbitrario en /streamer y el widget 'Live streams' de la p\u00e1gina de inicio colocando marcado en el t\u00edtulo de su transmisi\u00f3n de Twitch/YouTube. CSP est\u00e1 presente y bloquea la ejecuci\u00f3n de scripts en l\u00ednea, pero el problema sigue siendo un sumidero de inyecci\u00f3n de HTML del lado del servidor. Para activar esto, una cuenta de Lichess solo necesita satisfacer los requisitos normales de streamer y ser aprobada. Seg\u00fan Streamer.canApply, eso significa una cuenta con m\u00e1s de 2 d\u00edas de antig\u00fcedad con al menos 15 partidas, o una cuenta verificada/con t\u00edtulo. Despu\u00e9s de la aprobaci\u00f3n del moderador, una vez que el streamer se conecta en vivo, Lichess extrae el t\u00edtulo de la plataforma y lo renderiza en la interfaz de usuario tal cual. No se necesitan privilegios adicionales m\u00e1s all\u00e1 de un perfil de streamer aprobado normal. Esta vulnerabilidad se corrige con el commit 0d5002696ae705e1888bf77de107c73de57bb1b3."}], "id": "CVE-2026-35208", "lastModified": "2026-07-24T21:10:00.143", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "NONE", "baseScore": 5.4, "baseSeverity": "MEDIUM", "confidentialityImpact": "LOW", "integrityImpact": "LOW", "privilegesRequired": "LOW", "scope": "CHANGED", "userInteraction": "REQUIRED", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N", "version": "3.1"}, "exploitabilityScore": 2.3, "impactScore": 2.7, "source": "nvd@nist.gov", "type": "Primary"}], "cvssMetricV40": [{"cvssData": {"Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "Safety": "NOT_DEFINED", "attackComplexity": "LOW", "attackRequirements": "NONE", "attackVector": "NETWORK", "availabilityRequirement": "NOT_DEFINED", "baseScore": 5.3, "baseSeverity": "MEDIUM", "confidentialityRequirement": "NOT_DEFINED", "exploitMaturity": "NOT_DEFINED", "integrityRequirement": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "privilegesRequired": "LOW", "providerUrgency": "NOT_DEFINED", "subAvailabilityImpact": "NONE", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "userInteraction": "NONE", "valueDensity": "NOT_DEFINED", "vectorString": "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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X", "version": "4.0", "vulnAvailabilityImpact": "NONE", "vulnConfidentialityImpact": "LOW", "vulnIntegrityImpact": "LOW", "vulnerabilityResponseEffort": "NOT_DEFINED"}, "source": "security-advisories@github.com", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-35208", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "role": "CISA Coordinator", "timestamp": "2026-04-07T14:55:58.549189Z", "version": "2.0.3"}}]}, "published": "2026-04-06T21:16:20.273", "references": [{"source": "security-advisories@github.com", "tags": ["Patch"], "url": "https://github.com/lichess-org/lila/commit/0d5002696ae705e1888bf77de107c73de57bb1b3"}, {"source": "security-advisories@github.com", "tags": ["Exploit", "Vendor Advisory"], "url": "https://github.com/lichess-org/lila/security/advisories/GHSA-v7gh-939r-pfjq"}, {"source": "security-advisories@github.com", "tags": ["Exploit"], "url": "https://vimeo.com/1175908262"}], "sourceIdentifier": "security-advisories@github.com", "vulnStatus": "Analyzed", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-79"}, {"lang": "en", "value": "CWE-116"}], "source": "security-advisories@github.com", "type": "Secondary"}]}

{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[0,0d5002696ae705e1888bf77de107c73de57bb1b3)"}}], "enrichment": {"confidence": 86.0, "confidence_source": "matching", "scores": [{"score": 86.0, "source": "matching"}]}, "original": {"product": "lila", "source": "cna", "vendor": "lichess-org"}, "product": "lila", "vendor": "lichess"}], "analysis": {"en": {"generated_at": "2026-04-07T02:50:56.940879+00:00", "value": {"mitigation_remediation": ["Apply the patch that updates Lila to commit 0d5002696ae705e1888bf77de107c73de57bb1b3, which sanitises stream titles before rendering."], "summary": {"action": "Immediate Patch", "impact": "Server\u2011side injection of arbitrary HTML from stream titles"}, "threat_synthesis": {"affected_systems": "The vulnerability exists in the Lila application used by lichess.org. Any account that meets the standard streamer prerequisites\u2014older than two days with at least fifteen games, or a verified or titled account\u2014can enable the injection once the account is approved by a moderator and the streamer starts a live session. The flaw applies to all releases before the patch commit 0d5002696ae705e1888bf77de107c73de57bb1b3.", "description_and_impact": "Lichess.org renders third\u2011party stream titles directly into the page without sanitisation, creating a data sink that can be abused for cross\u2011site scripting. The flaw is a server\u2011side injection weakness (CWE\u2011116) and also an XSS vulnerability (CWE\u201179). A streamer with a normal approved account can craft a stream title containing malicious markup; that title then appears unchanged on the streamer page and in the home\u2011page live\u2011streams widget, exposing visitors to unintended content.", "risk_and_exploitability": "The CVSS score of 5.3 indicates moderate severity. No EPSS data is available, and the issue is not listed in CISA\u2019s KEV catalog. Exploitation requires only the normal permission to be an approved streamer. The attacker\u2019s payload is a stream title, so no extra system privileges are needed; the impact is confined to users who view the streamer page or the live\u2011streams widget, but the injected content can prompt phishing or other client\u2011side abuses."}}}}, "created": "2026-04-07T06:54:16.844620+00:00", "updated": "2026-04-07T09:37:18.102907+00:00", "vendors": ["lichess", "lichess$PRODUCT$lila"]}