Uncontrolled Recursion Affecting py3-nltk package, versions <3.9.4-r0


Severity

Recommended
0.0
high
0
10

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Threat Intelligence

EPSS
0.52% (42nd percentile)

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  • Snyk IDSNYK-WOLFILATEST-PY3NLTK-19517432
  • published4 Sept 2026
  • disclosed22 Aug 2026

Introduced: 22 Aug 2026

CVE-2026-66393  (opens in a new tab)
CWE-674  (opens in a new tab)

How to fix?

Upgrade Wolfi py3-nltk to version 3.9.4-r0 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream py3-nltk package and not the py3-nltk package as distributed by Wolfi. See How to fix? for Wolfi relevant fixed versions and status.

NLTK versions before 3.9.4 contain an unbounded recursion vulnerability in JSONTaggedDecoder.decode_obj() that allows attackers to cause denial of service by supplying deeply nested JSON structures. Attackers can craft JSON payloads exceeding the recursion limit to trigger an unhandled RecursionError that crashes the Python process.

CVSS Base Scores

version 3.1