CVE-2025-55303

Public Exploit
Unauthorized third-party images in Astro’s _image endpoint

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.

Category

6.9
CVSS
Severity: Medium
CVSS 4.0 •
EPSS 0.05%
Affected: withastro astro
Published at:
Updated at:

References

Link Tags
https://github.com/withastro/astro/security/advisories/GHSA-xf8x-j4p2-f749
https://github.com/withastro/astro/commit/4d16de7f95db5d1ec1ce88610d2a95e606e83820

Frequently Asked Questions

What is the severity of CVE-2025-55303?
CVE-2025-55303 has been scored as a medium severity vulnerability.
How to fix CVE-2025-55303?
To fix CVE-2025-55303, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2025-55303 being actively exploited in the wild?
It is possible that CVE-2025-55303 is being exploited or will be exploited in a near future based on public information. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2025-55303?
CVE-2025-55303 affects withastro astro.
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