Server-side Request Forgery (SSRF) Affecting nltk package, versions [,3.10.0)
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Start learning- Snyk IDSNYK-PYTHON-NLTK-18601824
- published10 Aug 2026
- disclosed9 Aug 2026
- creditoptimystical
Introduced: 9 Aug 2026
NewCVE-2026-12372 (opens in a new tab)How to fix?
Upgrade nltk to version 3.10.0 or higher.
Overview
nltk is a Natural Language Toolkit (NLTK) is a Python package for natural language processing.
Affected versions of this package are vulnerable to Server-side Request Forgery (SSRF) via the validate_network_url() address-policy check in nltk/pathsec.py. An attacker can make a strict-mode application send requests to shared-address-space or other non-global hosts by supplying a URL whose resolved IP falls in 100.64.0.0/10, which the filter does not reject. The vulnerable logic only blocked loopback, link-local, multicast, and private addresses, so requests to RFC 6598 carrier-grade NAT targets passed validation. That exposes internal or non-public network resources reachable from the host running NLTK’s network-loading helpers.