CVE-2025-14009
What it 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.
At a glance
- Exploitability
- Can be exploited over the network with a low-privilege account. High risk of data exposure, data tampering, service disruption.
- Exploit odds
- 1.0% chance of exploitation in the next 30 days (EPSS).
- Fix
- No patch or advisory is linked yet. Look at mitigations or restrict exposure.
Timeline
- ReservedThe CVE id was reserved by its CNA
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 1.0% in the next 30 days (EPSS).
- Severity: 8.8 HIGH (CVSS).
- Fix: none linked yet, which raises it.
Details
- Published
- Last modified
- Exploit probability
- 1.0% · EPSS, next 30 days
- Weakness
- CWE-94 · Code injection
- Record status
- Modified
Affected
- Nltk < 3.9.3
Attack profile CVSS 3.1 · 8.8
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Raw vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2025-14009.md and follow it. Check whether this project is affected by CVE-2025-14009. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
References
- https://huntr.com/bounties/49ecbc02-054e-4470-b2e0-b267936cc4e4
- https://access.redhat.com/errata/RHSA-2026:10184
- https://access.redhat.com/security/cve/CVE-2025-14009
- https://bugzilla.redhat.com/show_bug.cgi?id=2440724
- https://huntr.com/bounties/49ecbc02-054e-4470-b2e0-b267936cc4e4
- https://security.access.redhat.com/data/csaf/v2/vex/2025/cve-2025-14009.json