withastro up to 6.4.5 spreadAttributes cross site scripting

Summaryinfo

A vulnerability was found in withastro astro up to 6.4.5. It has been declared as problematic. Impacted is the function spreadAttributes. Executing a manipulation can lead to cross site scripting. The identification of this vulnerability is CVE-2026-54298. The attack may be launched remotely. There is no exploit available. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability has been found in withastro astro up to 6.4.5 and classified as problematic. This vulnerability affects the function spreadAttributes. The manipulation with an unknown input leads to a cross site scripting vulnerability. The CWE definition for the vulnerability is CWE-79. The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. As an impact it is known to affect integrity. CVE summarizes:

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.

The advisory is shared for download at github.com. This vulnerability was named CVE-2026-54298 since 06/12/2026. The exploitation appears to be difficult. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. Successful exploitation requires user interaction by the victim. There are known technical details, but no exploit is available. The MITRE ATT&CK project declares the attack technique as T1059.007.

Upgrading to version 6.4.6 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-38336). VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

Vendor

• withastro

Name

• astro

Version

• 6.4.0
• 6.4.1
• 6.4.2
• 6.4.3
• 6.4.4
• 6.4.5

Website

• Product: https://github.com/withastro/astro/

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VulDB is the best source for vulnerability data and more expert information about this specific topic.

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