[CVE-2026-78683] NLTK before 3.10.0 (affected versions <=3.9.4) contains an unsafe pickle deserialization vulnerabili…

Descripción técnica

NLTK before 3.10.0 (affected versions <=3.9.4) contains an unsafe pickle deserialization vulnerability in the TransitionParser.parse() method (nltk/parse/transitionparser.py). The method calls pickle_load() with the default restricted=False, routing deserialization through WarningUnpickler, which does not override find_class() and therefore permits arbitrary class resolution. When an application loads an attacker-crafted model file, embedded pickle gadget chains execute arbitrary Python code with the privileges of the user running the application. NLTK provides a RestrictedUnpickler for safe deserialization, but it is not used by production code paths. Fixed in 3.10.0.

Puntuación CVSS

Score: 9.6/10 — Severidad: CRITICAL — Estado NIST: Received

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H

Debilidades (CWE)

CWE-502

Fuente oficial

Publicado en NIST NVD.