{"cve":"CVE-2026-59727","nvd":{"published":"2026-07-27T20:16:40.153","modified":"2026-10-24T13:10:00.147","status":"Deferred","description":"Astro is a web framework for content-driven websites. In versions 3.10.0 through 7.0.3, when a transition:persist, transition:scope, or transition:persist-props directive is applied to a client-hydrated (client:*) component, Astro copied the directive value onto the rendered <astro-island> element without HTML-escaping it. If a developer reflects attacker-controlled input into one of these directives, an attacker can break out of the attribute and inject arbitrary HTML/JavaScript into the server-rendered output, resulting in reflected cross-site scripting (XSS). Exploitation requires the application developer to have written a non-idiomatic pattern — passing untrusted, request-derived input directly into a transition directive. Astro applications that do not route untrusted input into these directives are unaffected. This issue has been fixed in version 7.0.4.","cvss_v4":{"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N","score":2.1},"cvss_v3":null,"cwes":["CWE-79","CWE-83","CWE-116"],"references":["https://github.com/withastro/astro/commit/7ba0bb1dc7516e88caff9abd7767322af44b0294","https://github.com/withastro/astro/pull/17212","https://github.com/withastro/astro/releases/tag/astro@7.0.4","https://github.com/withastro/astro/security/advisories/GHSA-7pw4-f3q4-r2p2","https://github.com/withastro/astro/security/advisories/GHSA-7pw4-f3q4-r2p2"],"products":[],"source":"nvd","synced_at":"2026-10-24T16:53:27.712498749+00:00"},"epss":{"cve":"CVE-2026-59727","score":0.00393,"percentile":0.33233,"date":"2026-10-25"},"kev":null,"osv":[{"id":"GHSA-7pw4-f3q4-r2p2","url":"https://osv.dev/vulnerability/GHSA-7pw4-f3q4-r2p2","summary":"Astro: Cross-site scripting via unescaped transition:* directive values on hydrated islands","modified":"2026-08-12T20:45:07.788934236Z","packages":[{"ecosystem":"npm","name":"astro","purl":"pkg:npm/astro","ranges":[">=3.10.0 <7.0.4"],"fixed":["7.0.4"]}]}],"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."]}