Improper Access Control Affecting nltk package, versions *
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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- published11 Aug 2026
- disclosed7 Aug 2026
Introduced: 7 Aug 2026
NewCVE-2026-12261 (opens in a new tab)How to fix?
There is no fixed version for Echo:latest nltk.
NVD Description
Note: Versions mentioned in the description apply only to the upstream nltk package and not the nltk package as distributed by Echo.
See How to fix? for Echo:latest relevant fixed versions and status.
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.