{"cve":"CVE-2026-59729","nvd":{"published":"2026-07-27T20:16:40.303","modified":"2026-10-24T13:10:00.147","status":"Deferred","description":"Astro is a web framework for content-driven websites. Versions prior to 7.0.6 are vulnerable to XSS through unescaped spread attribute names in renderHTMLElement. The fix for CVE-2026-54298 (GHSA-jrpj-wcv7-9fh9) added an INVALID_ATTR_NAME_CHAR guard to addAttribute() so that spread-prop attribute names containing \"' >/= or whitespace are dropped. A second attribute-rendering path, renderHTMLElement() in packages/astro/src/runtime/server/render/dom.ts, has its own inline attribute loop that does not go through addAttribute() and was not updated. It interpolates the attribute name unescaped and only escapes the value, so untrusted prop keys spread onto a native-HTMLElement-subclass component can still break out of the attribute context. This issue has been fixed in version 7.0.6.","cvss_v4":{"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N","score":5.1},"cvss_v3":null,"cwes":["CWE-79"],"references":["https://github.com/withastro/astro/commit/5240e26c9dd91f9bc7140dcfacdb48d5a132830d","https://github.com/withastro/astro/pull/17251","https://github.com/withastro/astro/releases/tag/astro@7.0.6","https://github.com/withastro/astro/security/advisories/GHSA-f48w-9m4c-m7f5","https://github.com/withastro/astro/security/advisories/GHSA-f48w-9m4c-m7f5"],"products":[],"source":"nvd","synced_at":"2026-10-24T16:53:27.712498749+00:00"},"epss":{"cve":"CVE-2026-59729","score":0.00473,"percentile":0.40677,"date":"2026-10-26"},"kev":null,"osv":[{"id":"GHSA-f48w-9m4c-m7f5","url":"https://osv.dev/vulnerability/GHSA-f48w-9m4c-m7f5","summary":"Astro: XSS via unescaped spread attribute names in renderHTMLElement (incomplete fix for CVE-2026-54298)","modified":"2026-08-12T20:45:07.686847489Z","packages":[{"ecosystem":"npm","name":"astro","purl":"pkg:npm/astro","ranges":["<7.0.6"],"fixed":["7.0.6"]}]}],"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."]}