# CVE-2025-55303

## Summary

- **CVE ID:** CVE-2025-55303
- **Severity:** MEDIUM
- **CVSS Score:** 6.9 (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)
- **CWE:** CWE-79, CWE-115
- **Published:** Aug 19, 2025
- **Last Modified:** Mar 12, 2026

## 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 Products

- withastro — astro (>= 5.0.0-alpha.0, < 5.13.2)
- withastro — astro (< 4.16.18)

## References

- [CNA](https://github.com/withastro/astro/security/advisories/GHSA-xf8x-j4p2-f749)
- [CNA](https://github.com/withastro/astro/commit/4d16de7f95db5d1ec1ce88610d2a95e606e83820)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.64%
- **EPSS Percentile:** 48.4

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-11._