CVE-2026-50146 | Astro is a web framework. Prior to 6.3.3, when a component u… | CVSS 7.1 HIGH

Description

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.

Metadata

CVE ID: CVE-2026-50146
State: PUBLISHED
Assigner: GitHub_M
Reserved: 2026-06-03 18:49 UTC
Published: 2026-06-22 17:31 UTC
Last updated: 2026-06-22 17:31 UTC
Primary CWE: CWE-80
CWE-80: Improper Neutralization of Script-Related HTML Tags …
Vendor / Product: withastro / astro
Sources: cve.org · NVD

Severity & Metrics

7.1 HIGH CVSS 3.1

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:H/A:N

Affected products (1)

Vendor	Product	Platform	Versions
withastro	astro	—	< 6.3.3

Weakness (CWE)

CWE	Source	Description
CWE-80	cna	CWE-80: Improper Neutralization of Script-Related HTML Tags in a Web Page (Basic XSS)

CVSS scores (1)

Score	Severity	Version	Source	Vector
7.1	HIGH	3.1	cna	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:H/A:N

References (1)

https://github.com/withastro/astro/security/advisories/GHSA-8hv8-536x-4wqp https://github.com/withastro/astro/security/advisories/GHSA-8hv8-536x-4wqp