Vulnerability · Published Aug 19, 2025 · Assigned by GitHub_M
CVE-2025-55303Unauthorized third-party images in Astro’s _image endpoint
Medium 6.9
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 0.6% (higher than 51% of all known vulnerabilities). Ready-made attack tooling exists: Nuclei. Fixed versions are available - upgrade the affected package.
Official description
Astro is a web framework for content-driven websites. In versions of astro before 5.13.2 and 4.16.18, the image optimization endpoint in projects deployed with on-demand rendering allows images from unauthorized third-party domains to be served. On-demand rendered sites built with Astro include an /_image endpoint which returns optimized versions of images. 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. This vulnerability is fixed in 5.13.2 and 4.16.18.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| npm | @astrojs/node | 9.1.1 | GHSA-xf8x-j4p2-f749 |
| npm | astro | 5.13.2 | GHSA-xf8x-j4p2-f749 |
| npm | astro | 4.16.19 | GHSA-xf8x-j4p2-f749 |
Affected products (as reported)
Weakness: CWE-79, CWE-115 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N