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SSRF vulnerability in @opennextjs/cloudflare proactively mitigated for all Cloudflare customers

Workers

Mitigations have been put in place for all existing and future deployments of sites with the Cloudflare adapter for Open Next in response to an identified Server-Side Request Forgery (SSRF) vulnerability in the @opennextjs/cloudflare package.

The vulnerability stemmed from an unimplemented feature in the Cloudflare adapter for Open Next, which allowed users to proxy arbitrary remote content via the /_next/image endpoint.

This issue allowed attackers to load remote resources from arbitrary hosts under the victim site's domain for any site deployed using the Cloudflare adapter for Open Next. For example: https://victim-site.com/_next/image?url=https://attacker.com. In this example, attacker-controlled content from attacker.com is served through the victim site's domain (victim-site.com), violating the same-origin policy and potentially misleading users or other services.

References: https://www.cve.org/cverecord?id=CVE-2025-6087 ↗, https://github.com/opennextjs/opennextjs-cloudflare/security/advisories/GHSA-rvpw-p7vw-wj3m ↗

Impact

  • SSRF via unrestricted remote URL loading
  • Arbitrary remote content loading
  • Potential internal service exposure or phishing risks through domain abuse

Mitigation

The following mitigations have been put in place:

Server side updates to Cloudflare's platform to restrict the content loaded via the /_next/image endpoint to images. The update automatically mitigates the issue for all existing and any future sites deployed to Cloudflare using the affected version of the Cloudflare adapter for Open Next

Root cause fix: Pull request #727 ↗ to the Cloudflare adapter for Open Next. The patched version of the adapter has been released as @opennextjs/cloudflare@1.3.0

Package dependency update: Pull request cloudflare/workers-sdk#9608 ↗ to create-cloudflare (c3) to use the fixed version of the Cloudflare adapter for Open Next. The patched version of create-cloudflare has been published as create-cloudflare@2.49.3.

In addition to the automatic mitigation deployed on Cloudflare's platform, we encourage affected users to upgrade to @opennext/cloudflare v1.3.0 and use the remotePatterns ↗ filter in Next config if they need to allow-list external urls with images assets.