CVE-2026-0847

Description

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.

How to fix CVE-2026-0847

To remediate CVE-2026-0847, upgrade the affected package to a fixed version below.

• —no fix listed
• —no fix listed
• —upgrade to 3.9.3 or later

Is CVE-2026-0847 being exploited?

Low — EPSS is 0.1%, meaning exploitation activity has not been observed at scale.

Affected packages (3)

• from 0
• from 0, <= 3.9.2
• from 0, < 3.9.3

CVSS scores

References (6)

• ADVISORYgithub.com/advisories/GHSA-68j8-pq59-fqgm
• ADVISORYnvd.nist.gov/vuln/detail/CVE-2026-0847
• ADVISORYsecurity-tracker.debian.org/tracker/CVE-2026-0847
• PATCHgithub.com/nltk/nltk
• WEB