CVE-2026-54298
MediumCVSS 4.2Exploitation Probability (EPSS)
Low risk6th percentile — higher than 6% of all known CVEs
Summary
In versions prior to 6.4.6 of the Astro framework, the spreadAttributes function in the server-side rendering pipeline did not sanitize object keys against injection, allowing attackers to add arbitrary HTML attributes, including event handlers.
Risk Assessment
Organizations may be vulnerable to XSS attacks, which could lead to user data theft or session hijacking.
Recommendation
It is recommended to upgrade to version 6.4.6 or later to secure the application against this vulnerability.
Original NVD description (English source)
Astro is a web framework. Prior to 6.4.6, the spreadAttributes function in Astro's server-side rendering pipeline iterates over object keys and passes them directly to addAttribute, which interpolates the key into the HTML output without escaping. When a developer uses the spread syntax {...props} on an HTML element and the object keys come from an untrusted source (API, CMS, URL parameters), an attacker can inject arbitrary HTML attributes including event handlers like onmousemove, onclick, or break out of the attribute context entirely to inject new elements. This vulnerability is fixed in 6.4.6.