What is the CVSS score of CVE-2025-14009?

CVE-2025-14009 has a CVSS 3.0 base score of 10.0 (Critical). CVSS vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H. EPSS exploitation probability: 0.6%.

Which versions of Python are affected by CVE-2025-14009?

A critical zero-day vulnerability in the NLTK library's download functionality allows attackers to execute arbitrary code through malicious archive files, with a perfect CVSS score of 10.0.. A patch is available.

Is there a public PoC exploit available for CVE-2025-14009?

Yes, a public proof-of-concept exploit is available for CVE-2025-14009. Prioritise patching immediately. EPSS: 0.6%.

How to fix or mitigate CVE-2025-14009?

Within 24 hours: Identify all systems and applications using NLTK; disable NLTK's download functionality if not actively required for operations. Within 7 days: Implement network segmentation to restrict NLTK processes from accessing sensitive systems; audit logs for suspicious extraction activities. Within 30 days: Migrate to an alternative NLP library or await vendor patch; implement strict input validation on any archive handling; conduct forensic analysis for indicators of compromise.

Python CVE-2025-14009

CRITICAL

Code Injection (CWE-94)

2026-02-18 security@huntr.dev

GHSA-7p94-766c-hgjp

RCE Python Red Hat AI / ML Nltk Suse

10.0

CVSS 3.0

CVSS VectorNVD

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Changed

Confidentiality

High

Integrity

High

Availability

High

Lifecycle Timeline

Patch released

Mar 31, 2026 - 21:13 nvd

Patch available

Analysis Generated

Mar 12, 2026 - 21:55 vuln.today

PoC Detected

Mar 06, 2026 - 21:23 vuln.today

Public exploit code

CVE Published

Feb 18, 2026 - 18:24 nvd

CRITICAL 10.0

Blast Radius

ecosystem impact

† from your stack dependencies † transitive graph · vuln.today resolves 4-path depth

8 pypi packages depend on nltk (8 direct, 0 indirect)

Ecosystem-wide dependent count for version 3.9.3.

DescriptionNVD

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.

AnalysisAI

Critical code execution vulnerability in NLTK (Natural Language Toolkit) downloader component. The _unzip_iter function can be exploited to achieve arbitrary code execution through crafted downloads. CVSS 10.0, EPSS 0.57%. PoC available.

Technical ContextAI

CWE-94 code injection in NLTK's _unzip_iter function within the downloader. All NLTK versions are affected. The downloader processes ZIP files in a way that allows code execution.