Cloudflare has SSRF via redirect following through its image-binding-transform endpoint (incomplete fix for GHSA-qpr4)

## Summary The `fetch()` call for remote images in `packages/integrations/cloudflare/src/utils/image-binding-transform.ts` (line 28) uses the default `redirect: 'follow'` behavior. This allows the Cloudflare Worker to follow HTTP redirects to arbitrary URLs, bypassing the `isRemoteAllowed()` domain allowlist check which only validates the initial URL. All three other image fetch paths in the codebase correctly use `{ redirect: 'manual' }`. This is an incomplete fix for GHSA-qpr4-c339-7vq8. Confirmed on HEAD. ## Root Cause `image-binding-transform.ts` line 28: const content = await (isRemotePath(href) ? fetch(imageSrc) : assets.fetch(imageSrc)); Missing `{ redirect: 'manual' }`. The three protected paths: // image-passthrough-endpoint.ts:23 response = await fetch(href, { redirect: 'manual' }); // assets/endpoint/shared.ts:11 const res = await fetch(src, { redirect: 'manual' }); // assets/utils/remoteProbe.ts:53 const response = await fetch(url, { redirect: 'manual' }); ## PoC Demonstrated with Node.js that `fetch()` without `redirect: 'manual'` follows 302 redirects to arbitrary destinations: # Server A (allowed domain) returns 302 → Server B (internal) fetch('http://allowed:19741/img.jpg') → follows 302 → hits http://internal:19742/secret fetch('http://allowed:19741/img.jpg', {redirect:'manual'}) → returns 302, internal server NOT hit Attack path: attacker finds an open redirect on an allowed domain, crafts `/_image?href=https://allowed-cdn.com/redirect?url=http://internal-service/`, and the Worker follows the redirect to the unauthorized destination. ## Impact Bypasses the `image.domains` and `image.remotePatterns` allowlist for the default Cloudflare image service (`cloudflare-binding`). Enables blind SSRF to domains not in the allowlist. Same vulnerability class as GHSA-qpr4-c339-7vq8 (HIGH) which fixed the passthrough endpoint but missed this one. ## Suggested Fix const content = await (isRemotePath(href) ? fetch(imageSrc, { redirect: 'manual' }) : assets.fetch(imageSrc));

Source published

23 Apr 2026 21:52:03 UTC

Source modified

5 May 2026 16:05:51 UTC

Observed here

24 Oct 2026 13:17:17 UTC

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GitHub Advisory Database · CC-BY-4.0

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This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · GitHub Advisory Database · CC-BY-4.0. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS_V3 · CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:L

Publisher rating · LOW