GHSA-2JHM-W3MP-JCWR NLTK network URL validation permits SSRF to RFC 6598 shared-address-space hosts

A Server-Side Request Forgery SSRF vulnerability exists in nltk/nltk versions 3.9.4 and the current develop branch. The nltk.pathsec.validatenetworkurl function, intended to prevent SSRF by rejecting internal network addresses, fails to reject IPs in the RFC 6598 shared address space 100.64.0.0/1...

PT-2026-105470

A Server-Side Request Forgery SSRF vulnerability exists in nltk/nltk versions 3.9.4 and the current develop branch. The nltk.pathsec.validate network url function, intended to prevent SSRF by rejecting internal network addresses, fails to reject IPs in the RFC 6598 shared address space...