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.
History

Mon, 22 Jun 2026 21:30:00 +0000

Type Values Removed Values Added
First Time appeared Withastro
Withastro astro
Vendors & Products Withastro
Withastro astro

Mon, 22 Jun 2026 18:45:00 +0000

Type Values Removed Values Added
Description 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.
Title Astro: XSS via Unescaped Attribute Names in Spread Props
Weaknesses CWE-79
References
Metrics cvssV3_1

{'score': 4.2, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:N'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-06-22T17:33:15.734Z

Reserved: 2026-06-12T17:46:37.293Z

Link: CVE-2026-54298

cve-icon Vulnrichment

No data.

cve-icon NVD

No data.

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-06-22T21:15:04Z