CVE-2026-12252CWE-94

Untrusted JAR Code Execution in Multiple Stanford Interface Classes in nltk/nltk

High · published July 4, 2026

CVSS v3.0
7.8
EPSS
0%
Percentile
8.7
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.0
7.8 · HIGH
Vector
CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
CVSS v4.0
Not supplied
EPSS
0.00195 · 8.7th percentile
Weakness
CWE-94 · Improper Control of Generation of Code ('Code Injection')
Published
2026-07-04T00:58Z
EPSS history
Timeline
  • 04 JUL 00:58Z
    Untrusted JAR Code Execution in Multiple Stanford Interface Classes in nltk/nltk
    cvelistv5