Kurz gesagt
- CVE-2026-12261 ist eine Schwachstelle (MITTEL (CVSS 6.5)) in nltk, nltk (nltk).
- Wahrscheinlichkeit einer Ausnutzung in den nächsten 30 Tagen (EPSS): 0.21%, höher als bei 11.3% aller Schwachstellen.
- Abhilfe: auf 3.10.0 oder neuer aktualisieren.
| Package | Affected versions | Patched versions |
|---|
| nltk PyPI | < 3.10.0
| 3.10.0
|
| nltk | ≤ 3.9.4
| No fix yet |
Description
A vulnerability in nltk.downloader in nltk/nltk versions <= 3.9.4 allows for cross-package resource and model poisoning. The downloader extracts package archives into shared namespaces such as corpora/ and taggers/ instead of package-isolated roots, and validates package integrity only after the archive has been written and extracted. This design flaw enables one package to overwrite another package's trusted resources within the same namespace, making the changes immediately active through ordinary NLTK APIs. This issue persists across fresh interpreter restarts and can affect downstream workflows, including machine learning pipelines and reproducibility-sensitive environments.
NVD description
A vulnerability in `nltk.downloader` in nltk/nltk versions <= 3.9.4 allows for cross-package resource and model poisoning. The downloader extracts package archives into shared namespaces such as `corpora/` and `taggers/` instead of package-isolated roots, and validates package integrity only after the archive has been written and extracted. This design flaw enables one package to overwrite another package's trusted resources within the same namespace, making the changes immediately active through ordinary NLTK APIs. This issue persists across fresh interpreter restarts and can affect downstream workflows, including machine learning pipelines and reproducibility-sensitive environments.
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