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Vulnerabilities

Vulnerability · CVE-2025-14009

A critical vulnerability exists in the NLTK downloader component of nltk/nltk, affecting all versions.

Published Feb 18, 2026 · catalog updated Jul 15, 2026 · A critical vulnerability exists

Last checked Nov 12, 2026. A connected source was read within the last 7 days.

Check if you run it

No confirmed exploitation is on record for CVE-2025-14009. EPSS is 1.04%. Act only if a listed version of A critical vulnerability exists is installed.

Gaps on this record

  • The stored product name is a package slug. The name on this page is taken from the title (A critical vulnerability exists).
  • No version range is stored. A customer cannot check an installed version against this record.
  • No vendor fix or required action is stored. Compare the linked advisory before you change production.

Same product and reporting

Severity
High8.8
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
1.04%
Remediation
Vendor / distro source
Affected products
vendor nltk nltk/nltk unspecified ≤latest

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, lea

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • vendor nltk nltk/nltk unspecified ≤latestunspecified ≤latest

How to fix CVE-2025-14009

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2025-14009. EPSS is 1.04%. Act only if a listed version of A critical vulnerability exists is installed.

Which versions are affected?

Compare what you have installed with nltk nltk/nltk unspecified ≤latest unspecified ≤latest. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

No weakness class is stored. EPSS 1.04%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

No public source repository is identified for this product.

Timeline

Detection, updates, and resolution for this record.

  1. Feb 18, 2026 · EUVD

    Detected

    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 assu

  2. Jul 15, 2026 · EUVD

    Updated

    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 assu

Sources

  • CVE.orgVulnerability recordCVE-2025-14009

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2025-14009

    30-day exploitation probability 1.04%

    first.org
  • EUVDVulnerability recordEUVD-2025-207820

    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 pack

    euvd.enisa.europa.eu

References

Freshness

Last verified in this catalog Nov 12, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.

  • FIRST EPSSNov 9, 2026
  • CVE.orgNov 6, 2026
  • EUVDNov 5, 2026