CVE-2026-8445

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{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "packageURL": "pkg:pypi/justhtml", "product": "justhtml", "vendor": "EmilStenstrom", "versions": [{"lessThan": "1.12.0", "status": "affected", "version": "0", "versionType": "semver"}, {"status": "unaffected", "version": "1.12.0", "versionType": "semver"}]}], "source": "disclosure@vulncheck.com"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "justhtml versions <= 1.11.0 (fixed in 1.12.0) do not sufficiently escape HTML-significant characters (angle brackets) in text nodes when converting a parsed document to Markdown via to_markdown(). While a small set of Markdown metacharacters are escaped, characters such as < and > are preserved, so untrusted input that is safe in to_html() \u2014 including entity-decoded text (e.g. &lt;script&gt;) or text from RCDATA/RAWTEXT-parsed elements like <title>, <textarea>, <noscript>, and <plaintext> \u2014 can be emitted as raw HTML in the Markdown output, enabling a sanitizer bypass and potential cross-site scripting when that output is rendered."}, {"lang": "es", "value": "Las versiones de justhtml menor o igual que 1.11.0 (corregido en 1.12.0) no escapan suficientemente los caracteres significativos de HTML (corchetes angulares) en los nodos de texto al convertir un documento analizado a Markdown a trav\u00e9s de to_markdown(). Si bien un peque\u00f1o conjunto de metacaracteres de Markdown se escapan, caracteres como < y > se conservan, por lo que la entrada no confiable que es segura en to_html() - incluyendo texto decodificado por entidades (p. ej., <script>) o texto de elementos analizados como RCDATA/RAWTEXT como <title>, <textarea>, <noscript> y <plaintext> - puede ser emitido como HTML sin procesar en la salida de Markdown, lo que permite un bypass del saneador y potencial cross-site scripting cuando esa salida se renderiza."}], "id": "CVE-2026-8445", "lastModified": "2026-10-12T16:10:00.220", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 9.8, "baseSeverity": "CRITICAL", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 3.9, "impactScore": 5.9, "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": 9.3, "baseSeverity": "CRITICAL", "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:H/VI:H/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": "HIGH", "vulnIntegrityImpact": "HIGH", "vulnerabilityResponseEffort": "NOT_DEFINED"}, "source": "disclosure@vulncheck.com", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-8445", "options": [{"exploitation": "poc"}, {"automatable": "yes"}, {"technicalImpact": "total"}], "role": "CISA Coordinator", "timestamp": "2026-08-24T19:06:10.251827Z", "version": "2.0.3"}}]}, "published": "2026-08-23T14:16:54.957", "references": [{"source": "disclosure@vulncheck.com", "url": "https://github.com/EmilStenstrom/justhtml/security/advisories/GHSA-3rcm-vjrc-p45j"}, {"source": "disclosure@vulncheck.com", "url": "https://www.vulncheck.com/advisories/justhtml-before-sanitizer-bypass-via-markdown"}, {"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "url": "https://github.com/EmilStenstrom/justhtml/security/advisories/GHSA-3rcm-vjrc-p45j"}], "sourceIdentifier": "disclosure@vulncheck.com", "vulnStatus": "Deferred", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-79"}], "source": "disclosure@vulncheck.com", "type": "Secondary"}]}

{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[0,1.12.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "1.12.0"}}], "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": "2026-08-23T16:00:03.843909+00:00", "updated": "2026-08-23T16:39:36.294490+00:00", "vendors": ["emilstenstrom", "emilstenstrom$PRODUCT$justhtml"]}