7.8
HIGH CVSS 3.0
CVE-2026-12252
Untrusted JAR Code Execution in Multiple Stanford Interface Classes in nltk/nltk
Description

In nltk/nltk versions 3.9.3 and earlier, five Stanford interface classes (StanfordPOSTagger, StanfordNERTagger, StanfordParser, StanfordDependencyParser, and StanfordNeuralDependencyParser) are vulnerable to untrusted JAR code execution. These classes accept user-controllable JAR paths and execute them via the `java()` function, which invokes `subprocess.Popen()` without integrity verification. This vulnerability is identical to CVE-2026-0848, which was fixed for StanfordSegmenter by adding SHA256 verification. However, the fix was not applied to these additional classes, leaving them susceptible to arbitrary code execution when loading untrusted JAR files.

INFO

Published Date :

July 4, 2026, 12:58 a.m.

Last Modified :

July 4, 2026, 12:58 a.m.

Remotely Exploit :

No

Source :

@huntr_ai
Affected Products

The following products are affected by CVE-2026-12252 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.0 HIGH [email protected]
Solution
Update NLTK to a version that includes fixes for untrusted JAR code execution vulnerabilities.
  • Update NLTK to a patched version.
  • Verify JAR loading integrity checks.
  • Avoid loading untrusted JAR files.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-12252 vulnerability anywhere in the article.

EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.