What is CVE-2025-55303?

CVE-2025-55303 is a vulnerability in Withastro Astro, classified under Cross-site Scripting. Published 2025-08-19.

Is CVE-2025-55303 known to be exploited?

1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

XSS in Withastro Astro

CVE-2025-55303

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 s…

Vulnerability class: XSS (Cross-Site Scripting)

EPSS: 0.001 (31.5th percentile) — read the EPSS interpretation.

Affected products

Withastro Astro — versions >= 5.0.0-alpha.0, < 5.13.2, < 4.16.18

Weakness classification (CWE)

Public proof-of-concept exploits

fkie-cad/nvd-json-data-feeds

References

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

Frequently asked questions

What is CVE-2025-55303?: CVE-2025-55303 is a vulnerability in Withastro Astro, classified under Cross-site Scripting. Published 2025-08-19.
Is CVE-2025-55303 known to be exploited?: 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.