What is CVE-2026-0847?
A vulnerability in NLTK versions up to and including 3.9.2 allows arbitrary file read via path traversal in multiple CorpusReader classes, including WordListCorpusReader, TaggedCorpusReader, and BracketParseCorpusReader. These classes fail to properly sanitize or validate file paths, enabling attackers to traverse directories and access sensitive files on the server. This issue is particularly critical in scenarios where user-controlled file inputs are processed, such as in machine learning APIs, chatbots, or NLP pipelines. Exploitation of this vulnerability can lead to unauthorized access to sensitive files, including system files, SSH private keys, and API tokens, and may potentially escalate to remote code execution when combined with other vulnerabilities.
Timeline
- 2026-03-04Published to the U.S. National Vulnerability Database (NVD)
- 2026-07-15NVD record last updated
Affected product
Nltk
Remediation Steps
- Audit all WAGO switch deployments for CLI access points and hidden functions
- Restrict network access to switch CLI interfaces from non-authorized sources
- Apply WAGO firmware updates that patch CLI escape mechanism
- Implement out-of-band management networks for industrial switch administration
- Deploy network IDS/IPS signatures for WAGO CLI exploitation attempts
References
- https://huntr.com/bounties/fc69914f-36a9-4c18-8503-10013b39f966
- https://access.redhat.com/errata/RHSA-2026:10184
- https://access.redhat.com/errata/RHSA-2026:19712
- https://github.com/cisagov/CSAF/blob/develop/csaf_files/OT/white/2026/icsa-26-085-01.json
- https://www.wago.com/en/support/security
- https://nvd.nist.gov/vuln/detail/CVE-2026-0847
Referenced in our briefings & reports
- Vulnerability Priority Report – Week 5 of March 2026 (March 30 – April 5)
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