ssrfcheck Vulnerable to Server-Side Request Forgery (SSRF) and Incomplete List of Disallowed Inputs — CVE-2026-43929

Summary

### Summary `ssrfcheck` v1.3.0 (latest) fails to block Server-Side Request Forgery attacks when the target private IP address is encoded as an IPv4-mapped IPv6 address (e.g. `http://[::ffff:127.0.0.1]/`). The WHATWG URL parser built into Node.js silently normalizes the IPv4 notation inside the brackets to compressed hex form (`[::ffff:7f00:1]`) before the library's private-IP regex ever runs. The regex was written…

Product

npm: ssrfcheck

What to do

General, cautious steps (verify details in the official source):

• Prioritize patching or mitigation immediately (treat as actively risky).
• Identify affected product versions in your inventory and verify whether you are impacted.
• Apply vendor patches/updates or recommended mitigations as soon as available.
• Read the official advisory for exact affected versions and remediation steps.

Official advisory

• Read the official source
• CVE Record
• NVD

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