CVE-2026-50146
Published:June 22, 2026
Updated:June 29, 2026
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
https://github.com/withastro/astro.git (GITHUB):
Affected version(s) >=@astrojs/alpinejs@0.1.0 <6.3.3Fix Suggestion:
Update to version 6.3.3astro (NPM):
Affected version(s) >=0.0.0-i18n-routing-20231101144500 <6.3.3Fix Suggestion:
Update to version 6.3.3Related Resources (2)
Do you need more information?
Contact UsCVSS v4
Base Score:
7.1
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
PASSIVE
Vulnerable System Confidentiality
LOW
Vulnerable System Integrity
HIGH
Vulnerable System Availability
NONE
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
7.1
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
REQUIRED
Scope
UNCHANGED
Confidentiality
LOW
Integrity
HIGH
Availability
NONE
Weakness Type (CWE)
EPSS
Base Score:
0.18