{"id":"GHSA-f7gr-6p89-r883","summary":"Svelte affected by cross-site scripting via spread attributes in Svelte SSR","details":"Versions of svelte prior to 5.51.5 are vulnerable to cross-site scripting (XSS) during server-side rendering. When using spread syntax to render attributes from untrusted data, event handler properties are included in the rendered HTML output. If an application spreads user-controlled or external data as element attributes, an attacker can inject malicious event handlers that execute in victims' browsers.","aliases":["CVE-2026-27121"],"modified":"2026-07-17T21:13:25.731553708Z","published":"2026-02-19T15:18:33Z","database_specific":{"nvd_published_at":"2026-02-20T23:16:02Z","cwe_ids":["CWE-79"],"severity":"MODERATE","github_reviewed":true,"github_reviewed_at":"2026-02-19T15:18:33Z"},"references":[{"type":"WEB","url":"https://github.com/sveltejs/svelte/security/advisories/GHSA-f7gr-6p89-r883"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-27121"},{"type":"PACKAGE","url":"https://github.com/sveltejs/svelte"}],"affected":[{"package":{"name":"svelte","ecosystem":"npm","purl":"pkg:npm/svelte"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"5.51.5"}]}],"database_specific":{"last_known_affected_version_range":"\u003c= 5.51.4","source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/02/GHSA-f7gr-6p89-r883/GHSA-f7gr-6p89-r883.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:H/AT:P/PR:H/UI:N/VC:L/VI:N/VA:N/SC:H/SI:H/SA:N"}]}