chore(deps): update dependency astro to v5.15.9 [security]

[renovate]

This PR contains the following updates:

Package	Change	Age	Confidence
astro (source)	5.15.8 -> 5.15.9

GitHub Vulnerability Alerts

CVE-2025-65019

Summary

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.

Details

On-demand rendered sites built with Astro include an /_image endpoint for image optimization. While this endpoint is designed to restrict processing to local images and authorized remote domains (configured via image.domains or image.remotePatterns), a critical vulnerability exists in the underlying validation logic.

The isRemoteAllowed() function in packages/internal-helpers/src/remote.ts (lines 128-131) unconditionally allows ALL data: protocol URLs without any validation or sanitization. When combined with SVG images containing JavaScript, this creates a vector for XSS attacks.

Vulnerable Code:

/packages/ packages/internal-helpers/src/remote.ts lines 128-131
if (url.protocol === 'data:') {
    return true;  // ← Unconditionally allows ALL data: URLs!
}

The vulnerability manifests differently depending on the image endpoint implementation:

• Safe implementation: Server processes SVG and converts to raster format (PNG/JPEG), removing JavaScript
• Vulnerable implementation: Server redirects browser to raw SVG data URL, allowing JavaScript execution

PoC

1. Create a new minimal Astro project (astro@latest)

2. Configure it to use the Cloudflare adapter (@​astrojs/cloudflare@12.6.10)

3. Deploy to Cloudflare Pages or Workers.

4. Write page to load SVG Image like : SVG XSS Payload

5. Open directly the SVG file to show an alert (in read scenarios, the apps that use the framework will use CDN for example, to load SVG, depending that the framework is secure)

Impact

1. Stored XSS: Malicious URLs can be crafted to execute JavaScript in victim's browser
2. Session Hijacking: JavaScript can access cookies and session tokens
3. Account Takeover: Combined with CSRF, can perform unauthorized actions
4. Data Exfiltration: Sensitive information can be stolen and sent to attacker-controlled servers

References

• Vulnerable Function: packages/internal-helpers/src/remote.ts lines 128-131
• Similar Vulnerability:: https://dailycve.com/wordpress-stored-xss-via-svg-upload-cve-2025-2575-medium/

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Release Notes

withastro/astro (astro)

v5.15.9

Compare Source

Patch Changes

• #​14786 758a891 Thanks @​mef! - Add handling of invalid encrypted props and slots in server islands.

• #​14783 504958f Thanks @​florian-lefebvre! - Improves the experimental Fonts API build log to show the number of downloaded files. This can help spotting excessive downloading because of misconfiguration

• #​14791 9e9c528 Thanks @​Princesseuh! - Changes the remote protocol checks for images to require explicit authorization in order to use data URIs.

  In order to allow data URIs for remote images, you will need to update your astro.config.mjs file to include the following configuration:

  // astro.config.mjs
  import { defineConfig } from 'astro/config';
  
  export default defineConfig({
    images: {
      remotePatterns: [
        {
          protocol: 'data',
        },
      ],
    },
  });

• #​14787 0f75f6b Thanks @​matthewp! - Fixes wildcard hostname pattern matching to correctly reject hostnames without dots

  Previously, hostnames like localhost or other single-part names would incorrectly match patterns like *.example.com. The wildcard matching logic has been corrected to ensure that only valid subdomains matching the pattern are accepted.

• #​14776 3537876 Thanks @​ktym4a! - Fixes the behavior of passthroughImageService so it does not generate webp.

• Updated dependencies [9e9c528, 0f75f6b]:

  • @​astrojs/internal-helpers@​0.7.5
  • @​astrojs/markdown-remark@​6.3.9

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