cvedb.io
CVE-2026-12372
LOW · CVSS 3.7
EPSS exploitation probability: 0%
Published 2026-08-09T23:16:35.793 · Last modified 2026-08-09T23:16:35.793

Summary

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 (`100.64.0.0/10`). This occurs because Python's `ipaddress` module does not classify such addresses as `is_private` or `is_global`, and the current guard only checks `is_private` and a few explicit categories. An attacker who can influence a URL passed to NLTK's network-loading helpers can exploit this vulnerability to make a strict-mode application send requests to shared-address-space hosts, potentially exposing non-public infrastructure reachable from the application host. The impact is limited to S

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References

This product uses data from the NVD API but is not endorsed or certified by the NVD. Informational only; not professional security advice.