CVE-2026-12252 — Security Box Score

CVE · referencelatest edition

Reference page — cumulative record through Wednesday, August 19, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.

CVE-2026-12252HIGH

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

  AV  AC  PR  UI  S  C  I  A   CVSS    EPSS   %ile   KEV
   L   L   N   R  U  H  H  H    7.8   .0019    9.5     —

AFFECTED
  Product    Versions       Fixed
  nltk/nltk  unspecified –  —

TIMELINE
  Jun 15  Reserved by @huntr_ai
  Jul 4   EXPLOIT PUBLISHED — CVE-2026-12252 (nltk/nltk). Public exploit reference added.
  Jul 4   Published (CNA: @huntr_ai)

CWE-94 · CNA: @huntr_ai · CVSS v3.0 · 1 reference · NVD status: Analyzed

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.

Lifecycle

Complete event history — 3 events, chronological
Date	Event	Detail
June 15, 2026	Reserved	Reserved by @huntr_ai
July 4, 2026	EXPLOIT PUBLISHED	EXPLOIT PUBLISHED — CVE-2026-12252 (nltk/nltk). Public exploit reference added.
July 4, 2026	Published	Published (CNA: @huntr_ai)

Affected

Affected products and packages — 1 row
Vendor	Product / Package	Ecosystem	Version introduced	Fixed
nltk	nltk/nltk	—	unspecified	—

Weaknesses

CWE-94

References (1)

https://huntr.com/bounties/f5c93982-0cc9-4e2e-bb85-1b6ab29a2efb [Exploit, Third Party Advisory]

Authoritative record: CVE-2026-12252 at cve.org

Vendors: nltk

Weaknesses: CWE-94

About this page

This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2026-12252 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Wednesday, August 19, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.