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Fencer Vulns
critical 10.0

CVE-2025-14009 json

Zip Slip Vulnerability in nltk/nltk Leading to Remote Code Execution

published 2026-02-18 8 mo ago modified 2026-09-10 1 mo ago also GHSA-7p94-766c-hgjp , PYSEC-2026-96 , EUVD-2025-207820

cvss
10.0
version 3.0, CNA
cisa kev
Not listed
not in CISA's catalog
epss
1.0%
EPSS 1.0% chance of exploitation in 30 days, percentile 64%
public exploits
0
none known

Summary

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.

Patch / fix

  • pypi nltk 3.9.3
  • Red Hat Red Hat OpenShift AI 2.25 1775144403, 1776271296
  • nltk Debian 14 3.9.3-1

debian advisories DEBIAN-CVE-2025-14009

  • nltk Ubuntu Pro 14.04 LTS 2.0~b9-0ubuntu4.1~esm5
  • nltk Ubuntu Pro 16.04 LTS 3.1-1ubuntu0.1+esm3
  • nltk Ubuntu Pro 18.04 LTS 3.2.5-1ubuntu0.1+esm3
  • nltk Ubuntu Pro 20.04 LTS 3.4.5-2ubuntu0.1~esm3
  • nltk Ubuntu Pro 22.04 LTS 3.7-1ubuntu0.1~esm1
  • nltk Ubuntu Pro 24.04 LTS 3.8.1-1ubuntu0.1~esm1
  • nltk Ubuntu Pro 26.04 LTS 3.9.2-1ubuntu0.1~esm1

ubuntu advisories UBUNTU-CVE-2025-14009

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • python-nltk openSUSE Tumbleweed 3.9.1-3.1

opensuse advisories openSUSE-SU-2026:10226-1

  • py3-nltk Alpine 3.24 3.9.3-r0

alpine advisories ALPINE-CVE-2025-14009

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2025-14009 updated cvss 8.8

nltk: Zip Slip Vulnerability in nltk Leading to Code Execution

  • Red Hat OpenShift Lightspeed openshift-lightspeed/lightspeed-ocp-rag-rhel9, openshift-lightspeed/lightspeed-service-api-rhel9, openshift-lightspeed-tech-preview/lightspeed-rag-tool-rhel9 Red Hat OpenShift AI (RHOAI) rhoai/odh-pipeline-runtime-pytorch-llmcompressor-cuda-py312-rhel9, rhoai/odh-workbench-jupyter-pytorch-llmcompressor-cuda-py312-rhel9
    affected: workaround, no fix available
  • Red Hat OpenShift AI 2.25 rhoai 1775144403, rhoai 1776271296
    fixed: vendor fix RHSA-2026:10184
  • Red Hat OpenShift AI 2.25 rhoai 1776243157, rhoai 1776243163, rhoai 1776243192, rhoai 1776243217, rhoai 1776243229, rhoai 1776243238, +69 more
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
Proof of concept is public
Automatable
yes
Technical impact
total
Assessed
8 mo ago

Exploit prediction

1.04% chance of exploitation in the next 30 days, higher than 64% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • huntr.com https://huntr.com/bounties/49ecbc02-054e-4470-b2e0-b267936cc4e4 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.0 10.0 CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
CISA ADP 3.1 8.8 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CNA 3.1 8.8 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
OSV 3.0 10.0 CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
GitHub 3.0 10.0 CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

Affected packages

ecosystem package affected fixed in
pypi nltk
<3.9.3
3.9.3

Affected products

  • nltk nltk/nltk
  • Red Hat Red Hat OpenShift AI 2.25
  • Red Hat OpenShift Lightspeed
  • Red Hat Red Hat OpenShift AI (RHOAI)

Classification

Weakness
  • CWE-94 Improper Control of Generation of Code

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.