CVE-2026-3125

HIGH EPSS 28.2%
Published Mar 4, 20263mo ago · Modified Mar 9, 20263mo ago
7.7 CVSS 4.0
High
Find Similar
Published Mar 4, 2026 3mo ago
Last Modified Mar 9, 2026 3mo ago

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.

CVSS Details

Base Score
7.7
Exploitability
—
Impact
—
Vector string
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:H/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction None
Scope X

Threat Intelligence

EPSS Exploit Probability
28.2% percentile
Exploit & Patch Status
No Known Exploit
Patch Available

Weaknesses 2

CWE-706
CWE-918 Server-Side Request Forgery (SSRF) Validation

Affected Products 1

VendorProductVersionRange
opennextjsopennext_for_cloudflare* <1.17.1

References 4

  • github.com https://github.com/advisories/GHSA-rvpw-p7vw-wj3m
    Third Party Advisory
  • github.com https://github.com/opennextjs/opennextjs-cloudflare/pull/1147
    Issue TrackingPatch
  • cve.org https://www.cve.org/cverecord?id=CVE-2025-6087
    Third Party Advisory
  • npmjs.com https://www.npmjs.com/package/@opennextjs/cloudflare/v/1.17.1
    ProductRelease Notes

Remediation

  • github.com https://github.com/opennextjs/opennextjs-cloudflare/pull/1147
    Issue TrackingPatch