CVE-2025-14009

HIGH

CVSS v3.1: 8.8 · EPSS: 0.0071 (48.7 percentile)

NetworkNo user interactionCode Injection

Source data as of:

At a glance

Severity
HIGH
CVSS
8.8 v3.1 · NVD
EPSS
0.0071 (48.7 percentile) · FIRST.org
CISA KEV
No
Type
Code Injection · NVD CWE
Attack conditions (CVSS vector)
NetworkNo user interaction · Source: NVD Vector
Affected vendors
nltk
Published
2026-02-18 · Modified: 2026-06-30

CVSS / EPSS / KEV

CVSS v3.1 8.8 / 10 HIGH Source: NVD
EPSS 0.0071 48.7 percentile Source: FIRST.org
CISA KEV No Source: CISA

Source — CVSS: NVD · EPSS: FIRST.org · KEV: CISA. Data & Sources

Description

A critical vulnerability exists in the NLTK downloader component of nltk/nltk, affecting all versions. The _unzip_iter function in nltk/downloader.py uses zipfile.extractall() without performing path validation or security checks. This allows attackers to craft malicious zip packages that, when downloaded and extracted by NLTK, can execute arbitrary code. The vulnerability arises because NLTK assumes all downloaded packages are trusted and extracts them without validation. If a malicious package contains Python files, such as __init__.py, these files are executed automatically upon import, leading to remote code execution. This issue can result in full system compromise, including file system access, network access, and potential persistence mechanisms.

Record details

CVE ID
CVE-2025-14009
CVSS (v3.1)
8.8 (HIGH)
Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Exploitability subscore
2.8
Impact subscore
5.9
EPSS
0.0071 (48.7 percentile) — 2026-06-30
CISA KEV
No
Weakness (CWE)
CWE-94
Affected vendors
nltk
Affected configurations (CPE)
1
Published
2026-02-18
Modified
2026-06-30
Status
Modified

References

Reference URLs as listed by NVD, grouped by a mechanical match on the link's host/pattern. Labels describe the link type only.