← CVE Intelligence

CVE-2026-43929

ssrfcheck: Server-Side Request Forgery (SSRF) and Incomplete List of Disallowed Inputs PUBLISHED

Description (CNA)

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.

Affected (CNA)

Vendor / productVersions
felippe-regazio / ssrfcheckaffected <= 1.3.0

CWE

CWE-184, CWE-918

References

ADP enrichment

CISA-ADP

No English description supplied.