NIST deprecates RSA-2048 from 2030. Find every one of them before attackers do.
📦
📦 npm
Not in CISA KEV
MEDIUM severity

Astro allows unauthorized third-party images in _image endpointGHSA-xf8x-j4p2-f749

MEDIUMFix: withastro/astro@4d16de7

GHSA-xf8x-j4p2-f749 is a medium-severity (CVSS 6.1) Cross-site Scripting (XSS) vulnerability in astro. A fix is available for astro — see the affected versions and patch details below.

Also known asCVE-2025-55303
Published
Updated
Affected
3 pkgs
Patched
3 / 3
Exploits
None indexed
Exploitation data as of Nov 11, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

Proof-of-concept exploit code exists

  • CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
  • CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.

Exploitation and automatability from CISA’s SSVC triage for GHSA-xf8x-j4p2-f749.

EPSS Exploitation Probability

via FIRST.org ↗
0.7%probability of exploitation in next 30 days
Lower Risk+0.04%
Lower risk than most CVEs53th percentile — riskier than 53% of all scored CVEsHighest risk
0.00%0.39%0.78%1.18%0.1%0.7%May 26Sep 26Nov 26

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

3 pkgs affected

How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.

737other npm packages depend on this — each one inherits the vulnerability until it's patched upstream
astronpm
11.7Mdownloads / week
@astrojs/nodenpm
1.4Mdownloads / week

Description

Summary

In affected versions of astro, the image optimization endpoint in projects deployed with on-demand rendering allows images from unauthorized third-party domains to be served.

Details

On-demand rendered sites built with Astro include an /_image endpoint which returns optimized versions of images.

The /_image endpoint is restricted to processing local images bundled with the site and also supports remote images from domains the site developer has manually authorized (using the image.domains or image.remotePatterns options).

However, a bug in impacted versions of astro allows an attacker to bypass the third-party domain restrictions by using a protocol-relative URL as the image source, e.g. /_image?href=//example.com/image.png.

Proof of Concept

  1. Create a new minimal Astro project ([email protected]).

  2. Configure it to use the Node adapter (@astrojs/[email protected] — newer versions are not impacted):

    // astro.config.mjs
import { defineConfig } from 'astro/config';
import node from '@astrojs/node';

export default defineConfig({
	adapter: node({ mode: 'standalone' }),
});

  3. Build the site by running astro build.

  4. Run the server, e.g. with astro preview.

  5. Append /_image?href=//placehold.co/600x400 to the preview URL, e.g. http://localhost:4321/_image?href=//placehold.co/600x400

  6. The site will serve the image from the unauthorized placehold.co origin.

Impact

Allows a non-authorized third-party to create URLs on an impacted site’s origin that serve unauthorized image content. In the case of SVG images, this could include the risk of cross-site scripting (XSS) if a user followed a link to a maliciously crafted SVG.

Affected Packages

3 total 3 fixed
EcosystemPackageVulnerable rangeFix
📦npmastro≥ 5.0.0-alpha.0&&< 5.13.25.13.2npm install astro@5.13.2
📦npm@astrojs/nodeall versions9.1.1npm install @astrojs/node@9.1.1
📦npmastroall versions4.16.19npm install astro@4.16.19

Affected Products

1 product · 2 configurations
Application
astroastro
≥ 5.0.0 && < 5.13.2
range

Detection & mitigation playbook

Open-source dependency

  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for astro, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

  2. Fix

    Update astro to 5.13.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-xf8x-j4p2-f749 is resolved across your whole dependency graph.

  3. Workarounds

    Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.

How to detect GHSA-xf8x-j4p2-f749

A community-maintained Nuclei template exists for this CVE. You can scan for it directly:

nuclei -id ghsa-xf8x-j4p2-f749 -u https://target
Template
Astro - Unauthorized Third-Party Image Access
Severity
medium
Impact
Attackers can serve images from unauthorized third-party domains, potentially leading to information disclosure or content spoofing.
Remediation
Update to versions 5.13.2 or 4.16.18 or later.

Template by ProjectDiscovery nuclei-templates (theamanrawat), MIT licensed. View the full template. Scan only systems you are authorised to test.

Frequently Asked Questions

### Summary In affected versions of `astro`, the image optimization endpoint in projects deployed with on-demand rendering allows images from unauthorized third-party domains to be served. ### Details On-demand rendered sites built with Astro include an `/_image` endpoint which returns optimized versions of images. The `/_image` endpoint is restricted to processing local images bundled with the site and also supports remote images from domains the site developer has manually authorized (using the [`image.domains`](https://docs.astro.build/en/reference/configuration-reference/#imagedomains)
O3 Security · Impact-Aware SCA

Is GHSA-xf8x-j4p2-f749 in your dependencies?

Find it across npm, including transitive dependencies.

Scan my dependencies How O3 SCA works
Astro allows unauthorized third-party images in _image…