{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-8445","assignerOrgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","state":"PUBLISHED","assignerShortName":"VulnCheck","dateReserved":"2026-05-12T20:21:38.368Z","datePublished":"2026-08-23T13:34:13.886Z","dateUpdated":"2026-08-23T13:34:13.886Z"},"containers":{"cna":{"providerMetadata":{"orgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","shortName":"VulnCheck","dateUpdated":"2026-08-23T13:34:13.886Z"},"datePublic":"2026-03-18T00:00:00.000Z","title":"justhtml before 1.12.0 Sanitizer Bypass via Markdown","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() — including entity-decoded text (e.g. &lt;script&gt;) or text from RCDATA/RAWTEXT-parsed elements like <title>, <textarea>, <noscript>, and <plaintext> — can be emitted as raw HTML in the Markdown output, enabling a sanitizer bypass and potential cross-site scripting when that output is rendered."}],"problemTypes":[{"descriptions":[{"lang":"en","description":"Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')","cweId":"CWE-79","type":"CWE"}]}],"affected":[{"vendor":"EmilStenstrom","product":"justhtml","defaultStatus":"unaffected","packageURL":"pkg:pypi/justhtml","versions":[{"version":"0","status":"affected","versionType":"semver","lessThan":"1.12.0"},{"version":"1.12.0","status":"unaffected","versionType":"semver"}]}],"metrics":[{"cvssV4_0":{"Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","Safety":"NOT_DEFINED","attackComplexity":"LOW","attackRequirements":"NONE","attackVector":"NETWORK","baseScore":9.3,"baseSeverity":"CRITICAL","exploitMaturity":"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","version":"4.0","vulnAvailabilityImpact":"HIGH","vulnConfidentialityImpact":"HIGH","vulnIntegrityImpact":"HIGH","vulnerabilityResponseEffort":"NOT_DEFINED"},"format":"CVSS"},{"cvssV3_1":{"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"},"format":"CVSS"}],"references":[{"url":"https://github.com/EmilStenstrom/justhtml/security/advisories/GHSA-3rcm-vjrc-p45j","tags":["vendor-advisory"],"name":"GitHub Security Advisory (GHSA-3rcm-vjrc-p45j)"},{"name":"VulnCheck Advisory: justhtml before 1.12.0 Sanitizer Bypass via Markdown","tags":["third-party-advisory"],"url":"https://www.vulncheck.com/advisories/justhtml-before-sanitizer-bypass-via-markdown"}],"credits":[{"lang":"en","value":"kejcao","type":"reporter"}],"x_generator":{"engine":"vulncheck-endgame"}}}}