CVE-2026-4671

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{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "packageURL": "pkg:pypi/justhtml", "product": "justhtml", "vendor": "EmilStenstrom", "versions": [{"lessThan": "1.18.0", "status": "affected", "version": "0", "versionType": "semver"}, {"status": "unaffected", "version": "1.18.0", "versionType": "semver"}]}], "source": "disclosure@vulncheck.com"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "justhtml before 1.18.0 contains multiple low-severity denial-of-service issues in CSS selector handling and linkification. Applications that evaluate attacker-controlled selector strings (via query(), matches(), or selector-based transforms), run selector matching over very large untrusted documents, construct DOM trees from untrusted structure, or enable linkification over attacker-controlled text may consume disproportionate CPU or memory. Triggers include oversized selectors, large selector lists, oversized compound selectors, long combinator chains, deeply nested functional pseudo-classes, repeated token/positional matching, cyclic DOM graphs causing non-terminating traversal, and punctuation-heavy or trailing-bracket linkification input. These are availability-only concerns and do not by themselves allow script execution, data disclosure, or sanitizer bypass. Default JustHTML(sanitize=True) usage is not expected to be exposed, since selectors are normally supplied by application code."}, {"lang": "es", "value": "justhtml anterior a la versi\u00f3n 1.18.0 contiene m\u00faltiples problemas de denegaci\u00f3n de servicio de baja gravedad en el manejo de selectores CSS y la linkificaci\u00f3n. Las aplicaciones que eval\u00faan cadenas de selectores controladas por el atacante (a trav\u00e9s de query(), matches() o transformaciones basadas en selectores), ejecutan la coincidencia de selectores sobre documentos no confiables muy grandes, construyen \u00e1rboles DOM a partir de estructuras no confiables, o habilitan la linkificaci\u00f3n sobre texto controlado por el atacante pueden consumir una cantidad desproporcionada de CPU o memoria. Los desencadenantes incluyen selectores de tama\u00f1o excesivo, listas de selectores grandes, selectores compuestos de tama\u00f1o excesivo, cadenas de combinadores largas, pseudoclases funcionales profundamente anidadas, coincidencia repetida de tokens/posicional, gr\u00e1ficos DOM c\u00edclicos que causan un recorrido no terminante, y entrada de linkificaci\u00f3n con mucha puntuaci\u00f3n o corchetes finales. Estas son preocupaciones solo de disponibilidad y no permiten por s\u00ed mismas la ejecuci\u00f3n de scripts, la divulgaci\u00f3n de datos o la omisi\u00f3n del saneador. El uso predeterminado de JustHTML(sanitize=True) no se espera que est\u00e9 expuesto, ya que los selectores son normalmente proporcionados por el c\u00f3digo de la aplicaci\u00f3n."}], "id": "CVE-2026-4671", "lastModified": "2026-10-12T16:10:00.220", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 7.5, "baseSeverity": "HIGH", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "version": "3.1"}, "exploitabilityScore": 3.9, "impactScore": 3.6, "source": "disclosure@vulncheck.com", "type": "Secondary"}], "cvssMetricV40": [{"cvssData": {"Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "Safety": "NOT_DEFINED", "attackComplexity": "LOW", "attackRequirements": "NONE", "attackVector": "NETWORK", "availabilityRequirement": "NOT_DEFINED", "baseScore": 8.7, "baseSeverity": "HIGH", "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": "NONE", "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:N/UI:N/VC:N/VI:N/VA:H/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": "HIGH", "vulnConfidentialityImpact": "NONE", "vulnIntegrityImpact": "NONE", "vulnerabilityResponseEffort": "NOT_DEFINED"}, "source": "disclosure@vulncheck.com", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-4671", "options": [{"exploitation": "none"}, {"automatable": "yes"}, {"technicalImpact": "partial"}], "role": "CISA Coordinator", "timestamp": "2026-08-24T18:08:58.030472Z", "version": "2.0.3"}}]}, "published": "2026-08-23T14:16:53.293", "references": [{"source": "disclosure@vulncheck.com", "url": "https://github.com/EmilStenstrom/justhtml/security/advisories/GHSA-r8cj-3554-33mr"}, {"source": "disclosure@vulncheck.com", "url": "https://www.vulncheck.com/advisories/justhtml-before-denial-of-service-via-css-selector"}], "sourceIdentifier": "disclosure@vulncheck.com", "vulnStatus": "Deferred", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-400"}], "source": "disclosure@vulncheck.com", "type": "Secondary"}]}

{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[0,1.18.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "1.18.0"}}], "enrichment": {"confidence": 100.0, "confidence_source": "cna", "scores": [{"score": 100.0, "source": "cna"}]}, "original": {"product": "justhtml", "source": "cna", "vendor": "EmilStenstrom"}, "product": "justhtml", "vendor": "emilstenstrom"}], "created": "2026-08-23T15:15:04.833334+00:00", "updated": "2026-08-23T16:39:48.747478+00:00", "vendors": ["emilstenstrom", "emilstenstrom$PRODUCT$justhtml"]}