CVE-2026-0847: high-severity vulnerability in nltk/nltk
Path Traversal in nltk/nltk
Published · Updated
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21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 7.5epss 1.0%
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.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Affected products
nltk · nltk/nltkRelated CVEs — nltk/nltk
In the same product, most dangerous first.
CVE-2021-3828HIGHInefficient Regular Expression Complexity in nltk/nltkEPSS 1.6%CVE-2021-3842HIGHInefficient Regular Expression Complexity in nltk/nltkEPSS 1.6%CVE-2025-14009HIGHZip Slip Vulnerability in nltk/nltk Leading to Remote Code ExecutionEPSS 1.0%CVE-2026-0848CRITICALArbitrary Code Execution in NLTK StanfordSegmenter via Untrusted JAR LoadingEPSS 0.8%CVE-2026-0846HIGHArbitrary File Read via Absolute Path Input in nltk.util.filestring()EPSS 0.6%CVE-2026-12199HIGHUnauthenticated Denial of Service in nltk.app.wordnet_appEPSS 0.3%
References
https://access.redhat.com/errata/RHSA-2026:10184https://access.redhat.com/errata/RHSA-2026:19712https://access.redhat.com/security/cve/CVE-2026-0847https://bugzilla.redhat.com/show_bug.cgi?id=2444608https://huntr.com/bounties/fc69914f-36a9-4c18-8503-10013b39f966https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-0847.json