npm · @sveltejs/kit
SvelteKit : XSS via untrusted cache-control header in prerendered page
Applications that prerender pages and use setHeaders to set a cache-control header from an untrusted source are vulnerable to cross-site scripting (XSS).
SvelteKit inserts the header value into a <meta http-equiv="cache-control"> tag without escaping it. An attacker who can influence this value at prerender time can break out of the content attribute and inject HTML or JavaScript into the generated page. The injected code can then execute when users visit the page.
The fix escapes the header value before inserting it into the generated HTML. Upgrade to @sveltejs/kit version 3.0.0 or later.
Avoid forwarding untrusted cache-control header values with setHeaders on prerendered pages. Use a fixed, trusted cache policy instead.
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Check my repoSources: CISA KEV (public domain), OSV.dev & GitHub Advisory Database (CC-BY-4.0), FIRST EPSS, NVD/CWE (public domain). Served live from the Stateward advisory database.