AIKIDO-2026-10849

TL;DR

On the server, Astro renders hydrated client:* components with slot names embedded in astro-slot and data-astro-template attributes without HTML escaping. If slot names come from user-controlled input, an attacker can break out of the attribute context and inject markup or scripts into the SSR HTML response. Browsers that render that page can execute the injected content as reflected cross-site scripting. The fix applies escapeHTML() to slot name keys at both interpolation sites in the component renderer.