VulnerabilityAnalyzed

CVE-2025-55303

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.

MEDIUM 6.9EPSS 0.64%

Does this matter?

Lower severity and a low EPSS score (0.64%). Track it; it rarely justifies an emergency change on its own.

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.

CVSS 4.0: 6.9 MEDIUMCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
EPSS: 0.64% probability · 49th percentile
CISA KEV: Not listed
Weakness: CWE-79, CWE-115
Affected: astro/astro
Source: security-advisories@github.com

References

https://github.com/withastro/astro/commit/4d16de7f95db5d1ec1ce88610d2a95e606e83820Patch
https://github.com/withastro/astro/security/advisories/GHSA-xf8x-j4p2-f749Exploit, Vendor Advisory
https://github.com/withastro/astro/security/advisories/GHSA-xf8x-j4p2-f749Exploit, Vendor Advisory

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.