Junglewise Threat Intelligence

CVE-2026-0847: NLTK path traversal in CorpusReader classes

CVE-2026-0847 · Severity: high · CVSS 8.6 · Published 2026-03-04

Technologies: Red Hat Ansible Automation Platform 2, nltk (PyPI), NLTK Project Natural Language Toolkit. Vendors: Red Hat, PyPI, NLTK Project.

Executive brief

A security vulnerability has been identified in NLTK, a widely used library for natural language processing and artificial intelligence. This flaw allows an attacker to bypass security restrictions and read sensitive files from the server, such as system configuration files or private keys. This is particularly dangerous for organizations using NLTK in chatbots, machine learning pipelines, or automated text analysis tools where user input might be processed.

Technical details

A path traversal vulnerability exists in NLTK's CorpusReader classes, including WordListCorpusReader, TaggedCorpusReader, and BracketParseCorpusReader. The root cause is a failure to properly sanitize or validate file paths provided to these classes. A remote, unauthenticated attacker can exploit this by providing crafted file paths (e.g., using '../' sequences) to traverse the directory structure and read arbitrary files on the host system. This vulnerability is especially critical in applications that process user-controlled file inputs, such as NLP pipelines or ML APIs. Red Hat has released security advisories (RHSA-2026:10184 and RHSA-2026:19712) addressing this in their OpenShift AI products.

Affected products

  • NLTK Project NLTK <= 3.9.2
  • Red Hat Red Hat OpenShift AI 2.25, 3.3
  • Red Hat Red Hat Ansible Automation Platform 2 2

Timeline

  • 2026-03-04: disclosed: Vulnerability disclosed via huntr.dev
  • 2026-03-04: advisory: CVE-2026-0847 published
  • 2026-04-23: patched: Red Hat released security advisory RHSA-2026:10184

References

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