Threats Tagged 'cve-2026-71513'

NLTK versions before 3.10.3 contain a remote code execution vulnerability in the AllowlistUnpickler component. The vulnerability arises because the validation only checks the pickle module string but not the full global name, allowing attackers to exploit attribute traversal to invoke callables outside the intended allowlist. This can be triggered by crafting malicious transition-parser models that execute arbitrary commands when loaded via TransitionParser.parse.

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.