CVE-2026-0848

What it is

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.

At a glance

Exploitability

Can be exploited over the network without logging in. High risk of data exposure, data tampering, service disruption.

Exploit odds

0.8% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2026-03-05 21:16 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-06-17 10:11 UTC Last updatedMost recent change to the record

Details

Published

2026-03-05 21:16 UTC

Last modified

2026-06-17 10:11 UTC

Exploit probability

0.8% · EPSS, next 30 days

Weakness

CWE-20 · Improper input validation

Record status

Analyzed

Affected

• Nltk ≤ 3.9.2

Attack profile CVSS 3.0 · 10.0

Attack vector

Network

Complexity

Low

Privileges needed

None

User interaction

None

Scope

Changed

Confidentiality

High

Integrity

High

Availability

High