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

Summary

CVE	CVE-2025-14009
State	PUBLISHED
Assigner	@huntr_ai
Source Priority	CVE Program / NVD first with legacy fallback
Published	2026-02-18 18:24:19 UTC
Updated	2026-06-30 03:16:43 UTC
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.

Risk And Classification

Primary CVSS: v3.1 8.8 HIGH from ADP

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS: 0.007900000 probability, percentile 0.517400000 (date 2026-07-01)

Problem Types: CWE-94 | CWE-94 CWE-94 Improper Control of Generation of Code | CWE-94 Improper Control of Generation of Code ('Code Injection')

Version	Source	Type	Score	Severity	Vector
3.1	ADP	CVSS	8.8	HIGH	`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`
3.1	0b0ca135-0b70-47e7-9f44-1890c2a1c46c	Secondary	8.8	HIGH	`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`
3.0	[email protected]	Secondary	10	CRITICAL	`CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H`
3.0	CNA	DECLARED	10	CRITICAL	`CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H`

CVSS v3.1 Breakdown

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS v3.0 Breakdown

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Changed

Confidentiality

High

Integrity

High

Availability

High

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

NVD Known Affected Configurations (CPE 2.3)

Type	Vendor	Product	Version	Update	Edition	Language
Application	Nltk	Nltk	All	All	All	All

Vendor Declared Affected Products

Source	Vendor	Product	Version	Platforms
CNA	Nltk	Nltk/nltk	affected unspecified latest custom	Not specified
ADP	Red Hat	Red Hat OpenShift AI 2.25	Not specified	Not specified
ADP	Red Hat	OpenShift Lightspeed	Not specified	Not specified
ADP	Red Hat	Red Hat OpenShift AI RHOAI	Not specified	Not specified

References

Reference	Source	Link	Tags
access.redhat.com/security/cve/CVE-2025-14009	0b0ca135-0b70-47e7-9f44-1890c2a1c46c	access.redhat.com
access.redhat.com/errata/RHSA-2026:10184	0b0ca135-0b70-47e7-9f44-1890c2a1c46c	access.redhat.com
huntr.com/bounties/49ecbc02-054e-4470-b2e0-b267936cc4e4	134c704f-9b21-4f2e-91b3-4a467353bcc0	huntr.com	Exploit, Third Party Advisory
bugzilla.redhat.com/show_bug.cgi	0b0ca135-0b70-47e7-9f44-1890c2a1c46c	bugzilla.redhat.com
security.access.redhat.com/data/csaf/v2/vex/2025/cve-2025-14009.json	0b0ca135-0b70-47e7-9f44-1890c2a1c46c	security.access.redhat.com
CVE Program record	CVE.ORG	www.cve.org	canonical
NVD vulnerability detail	NVD	nvd.nist.gov	canonical, analysis

No vendor comments have been submitted for this CVE.

Additional Advisory Data

Source	Time	Event
ADP	2026-02-18T19:03:28.564Z	Reported to Red Hat.
ADP	2026-02-18T17:45:17.573Z	Made public.

Solutions

ADP: RHSA-2026:10184: Red Hat OpenShift AI 2.25

Workarounds

ADP: Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.

There are currently no legacy QID mappings associated with this CVE.