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OpenAdvisories
High · 7.8 CVE-2026-12252 EUVD-2026-41656GHSA-9r6g-266r-89x4PYSEC-2026-2085

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

Published Jul 4, 2026 · Updated Jul 6, 2026 · Assigned by @huntr_ai

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.

Affected products

VendorProductAffectedFixed
nltk nltk/nltk unspecified – ≤ latest —

Fixed in Linux distributions

Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.

ReleasePackageFixed inAdvisory
Debian 14 nltk 3.10.3-1 —
Debian 13 nltk No fix yet —
Debian 12 nltk No fix yet —
ReleasePackageFixed inAdvisory
Ubuntu 26.10 nltk No fix yet —
Ubuntu 25.10 nltk No fix yet —
Show 7 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
Ubuntu Pro 26.04 LTS nltk No fix yet —
Ubuntu Pro 24.04 LTS nltk No fix yet —
Ubuntu Pro 22.04 LTS nltk No fix yet —
Ubuntu Pro 20.04 LTS nltk No fix yet —
Ubuntu Pro 18.04 LTS nltk No fix yet —
Ubuntu Pro 16.04 LTS nltk No fix yet —
Ubuntu Pro 14.04 LTS nltk No fix yet —
ReleasePackageFixed inAdvisory
openSUSE Tumbleweed python-nltk 3.10.3-1.1 openSUSE-SU-2026:11587-1

Affected packages

EcosystemPackageAffectedFixedRecord
PyPI nltk < 3.9.4 3.9.4 GHSA-9r6g-266r-89x4

Advisories 1

References