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National Vulnerability Database

National Vulnerability Database

NVD

National Vulnerability Database
  1. Vulnerabilities

CVE-2026-43929 Detail

Description

ssrfcheck is a library that checks if a string contains a potential SSRF attack. In 1.3.0 and earlier, ssrfcheck 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 to match dot-notation only and therefore never matches any real input — all seven IANA private IPv4 ranges, including the AWS/GCP/Azure metadata address 169.254.169.254, are bypassed. Any application using isSSRFSafeURL() to guard HTTP requests made with user-supplied URLs is fully exposed to SSRF.


Metrics

 
NVD enrichment efforts reference publicly available information to associate vector strings. CVSS information contributed by other sources is also displayed.
CVSS 4.0 Severity and Vector Strings:

NIST CVSS score
NIST: NVD
N/A
NVD assessment not yet provided.

References to Advisories, Solutions, and Tools

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URL Source(s) Tag(s)
https://github.com/felippe-regazio/ssrfcheck/security/advisories/GHSA-j4rj-2jr5-m439 CISA-ADP, GitHub, Inc.

Weakness Enumeration

CWE-ID CWE Name Source
CWE-184 Incomplete List of Disallowed Inputs GitHub, Inc.  
CWE-918 Server-Side Request Forgery (SSRF) GitHub, Inc.  

Change History

2 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2026-43929
NVD Published Date:
05/12/2026
NVD Last Modified:
05/13/2026
Source:
GitHub, Inc.