CVE-2025-55303

Unauthorized third-party images in Astro’s _image endpoint

State: Published
Severity: 6.9 Medium
Published: Aug 19, 2025
Updated: Aug 19, 2025
Reserved: Aug 12, 2025

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.

Scores

CVSS	Score	Vector	Source
4.0	6.9 Medium	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	GitHub_M

Weaknesses

CWE-79 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CWE-115 Misinterpretation of Input

Affected Products

Product	Versions
astrowithastro	>= 5.0.0-alpha.0, < 5.13.2Affected < 4.16.18Affected

References

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