Astro: Netlify Image CDN allowlist bypass enables SSRF
Summary
The @astrojs/netlify adapter generated regular expressions for Netlify Image CDN remote-image allowlists without anchoring them to the beginning of the URL. Netlify evaluates these expressions with RegExp.test(), so an allowed image origin appearing anywhere in a URL, including its path or query string, could satisfy the allowlist.
For example, an application allowing images.example.com could accept a source URL such as:
http://127.0.0.1:6379/?url=https://images.example.com/image.pngThe allowlist matched the approved origin in the query string, but Netlify parsed and fetched the URL whose actual host was 127.0.0.1.
Impact
An unauthenticated attacker can bypass the configured image.domains or image.remotePatterns allowlist through the public /.netlify/images endpoint and cause Netlify Image CDN to make requests to attacker-selected URLs. This may allow probing or reaching internal services, depending on Netlify's network-level egress protections.
The Image CDN attempts to transform responses as images, which limits direct response exfiltration. No confidentiality or integrity impact has been demonstrated.
Affected versions
@astrojs/netlify versions from 5.2.0 through 8.2.3.
Patches
Fixed in @astrojs/netlify 8.2.4. Generated remote-image allowlist expressions are now anchored to both the beginning and end of the source URL.
Workarounds
Upgrade to @astrojs/netlify 8.2.4 or later. Before upgrading, disable Netlify Image CDN by setting imageCDN: false in the adapter configuration, or remove remote image allowlist entries.
Credits
Reported by @pacocartones.
Affected software
Click a technology to see all vulnerabilities affecting it.
| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| npm package | @astrojs/netlify | >= 5.2.0, < 8.2.4 | 8.2.4 |
References
- https://github.com/withastro/astro/security/advisories/GHSA-4233-jc72-56c5
- https://nvd.nist.gov/vuln/detail/CVE-2026-102983
- https://github.com/withastro/astro/pull/17752
- https://github.com/withastro/astro/commit/e362d4cf540b27730482455c8fc02efe57d16702
- https://github.com/withastro/astro
- https://github.com/withastro/astro/releases/tag/@astrojs/netlify@8.2.4
- CVSS vector
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N- Weakness (CWE)
CWE-625, CWE-918- Platform
- npm
- Package
@astrojs/netlify- Disclosed
- 30.09.2026
- Updated
- 11.10.2026 10:22
Sources and licenses
OSV / GitHub Advisory Database - GHSA-4233-jc72-56c5 - CC BY 4.0
Vulnerability history: @astrojs/netlify
All published vulnerabilities of this package (npm package), newest first. Shows whether this is a one-off slip or a package that needs watching.
- Total entries
- 3
- First → latest
- 06.2026 09.2026
- Without a fix
- 0
- Exploited in attacks
- 0
Severity breakdown
- Medium 2
- Low 1
Disclosures per year
- 2026: 3
-
Astro: Netlify Image CDN allowlist bypass enables SSRF this entry
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