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: ```text http://127.0.0.1:6379/?url=https://images.example.com/image.png ``` The 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
GHSA-4233-jc72-56c5
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: osv:GHSA-4233-jc72-56c5
@astrojs/netlify
Source reference: /affected/0/package/name
- Affected versions
- Not stated in this record
- Fixed versions
- 8.2.4
Source reference:
/affected/0/ranges - Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"ranges": [
{
"type": "SEMVER",
"events": [
{
"introduced": "5.2.0"
},
{
"fixed": "8.2.4"
}
]
}
],
"package": {
"name": "@astrojs/netlify",
"purl": "pkg:npm/%40astrojs/netlify",
"ecosystem": "npm"
},
"database_specific": {
"source": "https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/09/GHSA-4233-jc72-56c5/GHSA-4233-jc72-56c5.json",
"last_known_affected_version_range": "<= 8.2.3"
}
}
]- Related CVEs
- CVE-2026-102983
Source reference:
/aliases
Publisher severity
No explicit severity was provided.
- Event
- #51903 · Revision 1
- Added to Heist Feed
- Publisher date