Vulnerability · Published Nov 19, 2025 · Assigned by GitHub_M

CVE-2025-65019Astro Cloudflare adapter has a Stored Cross Site Scripting vulnerability in /_image endpoint

Medium 5.4

In plain English

A medium-severity cross-site scripting in astro from withastro. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 20% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)5.4Medium
Exploit odds (30 days)0.3%top 80.1% of all CVEs
Exploited in the wildNo reportsCISA SSVC: poc
Attack toolingNoneno public tooling known

Official description

Astro is a web framework. Prior to version 5.15.9, when using Astro's Cloudflare adapter (@astrojs/cloudflare) with output: 'server', the image optimization endpoint (/_image) contains a critical vulnerability in the isRemoteAllowed() function that unconditionally allows data: protocol URLs. This enables Cross-Site Scripting (XSS) attacks through malicious SVG payloads, bypassing domain restrictions and Content Security Policy protections. This issue has been patched in version 5.15.9.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
npmastro5.15.9GHSA-fvmw-cj7j-j39q

Affected products (as reported)

VendorProductVersions
withastro astro < 5.15.9

Weakness: CWE-79 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N

References