{"cve":"CVE-2026-77088","nvd":{"published":"2026-08-23T14:16:54.433","modified":"2026-10-12T16:10:00.220","status":"Deferred","description":"justhtml versions 0.9.0 through 1.21.0 contain a cross-site scripting vulnerability in to_markdown() where inline code spans fail to account for blank lines as block boundaries. Attackers can inject blank lines into code or pre element text to break the inline span, causing sanitized HTML to be emitted unescaped and re-parsed as live Markdown by compliant renderers.","cvss_v4":{"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N","score":5.3},"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","score":6.1},"cwes":["CWE-79"],"references":["https://github.com/EmilStenstrom/justhtml/security/advisories/GHSA-jf6w-2mvx-633j","https://www.vulncheck.com/advisories/justhtml-through-cross-site-scripting-via-code-span"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:49:38.260478770+00:00"},"epss":{"cve":"CVE-2026-77088","score":0.00263,"percentile":0.17924,"date":"2026-10-25"},"kev":null,"osv":[{"id":"GHSA-jf6w-2mvx-633j","url":"https://osv.dev/vulnerability/GHSA-jf6w-2mvx-633j","summary":"justhtml: to_markdown() code-span blank-line breakout enables XSS","modified":"2026-08-24T03:55:59.663337177Z","packages":[{"ecosystem":"PyPI","name":"justhtml","purl":"pkg:pypi/justhtml","ranges":[">=0.9.0 <1.22.0"],"fixed":["1.22.0"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}