NLTK versions <=3.9.2 are vulnerable to arbitrary code execution due to improper input validation in the StanfordSegmenter module. The module dynamically loads external Java .jar files without verification or sandboxing. An attacker can supply or replace the JAR file, enabling the execution of arbitrary Java bytecode at import time. This vulnerability can be exploited through methods such as model poisoning, MITM attacks, or dependency poisoning, leading to remote code execution. The issue arises from the direct execution of the JAR file via subprocess with unvalidated classpath input, allowing malicious classes to execute when loaded by the JVM.
History

Fri, 06 Mar 2026 17:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'poc', 'Technical Impact': 'total'}, 'version': '2.0.3'}


Fri, 06 Mar 2026 15:30:00 +0000

Type Values Removed Values Added
First Time appeared Nltk
Nltk nltk/nltk
Vendors & Products Nltk
Nltk nltk/nltk

Thu, 05 Mar 2026 21:00:00 +0000

Type Values Removed Values Added
Description NLTK versions <=3.9.2 are vulnerable to arbitrary code execution due to improper input validation in the StanfordSegmenter module. The module dynamically loads external Java .jar files without verification or sandboxing. An attacker can supply or replace the JAR file, enabling the execution of arbitrary Java bytecode at import time. This vulnerability can be exploited through methods such as model poisoning, MITM attacks, or dependency poisoning, leading to remote code execution. The issue arises from the direct execution of the JAR file via subprocess with unvalidated classpath input, allowing malicious classes to execute when loaded by the JVM.
Title Arbitrary Code Execution in NLTK StanfordSegmenter via Untrusted JAR Loading
Weaknesses CWE-20
References
Metrics cvssV3_0

{'score': 10, 'vector': 'CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H'}


cve-icon MITRE

Status: PUBLISHED

Assigner: @huntr_ai

Published:

Updated: 2026-03-06T16:31:01.105Z

Reserved: 2026-01-10T23:59:44.115Z

Link: CVE-2026-0848

cve-icon Vulnrichment

Updated: 2026-03-06T16:30:50.393Z

cve-icon NVD

Status : Received

Published: 2026-03-05T21:16:14.263

Modified: 2026-03-06T17:16:25.273

Link: CVE-2026-0848

cve-icon Redhat

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