CVEvulnerability

CVE-2026-43929

8.2 HIGH Published 2026-05-12 Modified 2026-10-26 Official page ↗
Status
Deferred
Published
2026-05-12
Last modified
2026-10-26
Assigner
[email protected]
CVSS 3.1 ([email protected])
8.2 HIGH — CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N
Weaknesses
CWE-184, CWE-918

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.

Related

Weakness · CWE (2)

  • CWE-184 Incomplete List of Disallowed Inputs weakness
  • CWE-918 Server-Side Request Forgery weakness

References