CVE-2026-0848

Publication date 6 March 2026

Last updated 6 March 2026


Ubuntu priority

Cvss 3 Severity Score

10.0 · Critical

Score breakdown

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.

Status

Package Ubuntu Release Status
nltk 25.10 questing
Needs evaluation
24.04 LTS noble
Needs evaluation
22.04 LTS jammy
Needs evaluation
20.04 LTS focal
Needs evaluation
18.04 LTS bionic
Needs evaluation
16.04 LTS xenial
Needs evaluation
14.04 LTS trusty
Needs evaluation

Severity score breakdown

Parameter Value
Base score 10.0 · Critical
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Scope Changed
Confidentiality High
Integrity impact High
Availability impact High
Vector CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H