high7.1
CVE-2026-50146
Astro: Reflected XSS via unescaped slot name
Impact
Astro is a web framework. Prior to 6.3.3, when a component uses a client:* directive, Astro inserts named slot content into a data-astro-template attribute without HTML escaping the slot name allowing an attacker to break out of the attribute context and inject arbitrary HTML, resulting in reflected XSS during SSR. This vulnerability is fixed in 6.3.3.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| npm | astro | < 6.3.3 | 6.3.3 |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Astro | Astro | before 6.3.3 |