nltk nltk/downloader.py _unzip_iter code injection

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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8.6$0-$5k0.00

Summaryinfo

A vulnerability classified as critical has been found in nltk. Affected is the function _unzip_iter of the file nltk/downloader.py. Performing a manipulation results in code injection. This vulnerability was named CVE-2025-14009. The attack may be initiated remotely. There is no available exploit.

Detailsinfo

A vulnerability classified as critical has been found in nltk (version now known). This affects the function _unzip_iter of the file nltk/downloader.py. The manipulation with an unknown input leads to a code injection vulnerability. CWE is classifying the issue as CWE-94. The product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

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.

The advisory is shared at huntr.com. This vulnerability is uniquely identified as CVE-2025-14009 since 12/04/2025. The exploitability is told to be easy. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. Technical details are known, but no exploit is available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 03/06/2026). MITRE ATT&CK project uses the attack technique T1059 for this issue.

The vulnerability scanner Nessus provides a plugin with the ID 299599 (Linux Distros Unpatched Vulnerability : CVE-2025-14009), which helps to determine the existence of the flaw in a target environment.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the vulnerability database at Tenable (299599). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Name

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 8.6
VulDB Meta Temp Score: 8.6

VulDB Base Score: 7.3
VulDB Temp Score: 7.3
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 10.0
CNA Vector (@huntr_ai): 🔒

CVSSv2info

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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Code injection
CWE: CWE-94 / CWE-74 / CWE-707
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 299599
Nessus Name: Linux Distros Unpatched Vulnerability : CVE-2025-14009

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: no mitigation known
Status: 🔍

0-Day Time: 🔒

Timelineinfo

12/04/2025 CVE reserved
02/18/2026 +76 days Advisory disclosed
02/18/2026 +0 days VulDB entry created
03/06/2026 +16 days VulDB entry last update

Sourcesinfo

Advisory: huntr.com
Status: Not defined

CVE: CVE-2025-14009 (🔒)
GCVE (CVE): GCVE-0-2025-14009
GCVE (VulDB): GCVE-100-346653

Entryinfo

Created: 02/18/2026 19:22
Updated: 03/06/2026 22:45
Changes: 02/18/2026 19:22 (61), 02/19/2026 22:08 (2), 03/06/2026 22:45 (1)
Complete: 🔍
Cache ID: 216::103

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

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