Uncontrolled Recursion Affecting nltk package, versions *


Severity

Recommended
0.0
medium
0
10

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Threat Intelligence

EPSS
0.46% (37th percentile)

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  • Snyk IDSNYK-ECHOLATEST-NLTK-19402145
  • published28 Aug 2026
  • disclosed27 Aug 2026

Introduced: 27 Aug 2026

CVE-2026-81724  (opens in a new tab)
CWE-674  (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.

NLTK before 3.10.3 contains an uncontrolled recursion vulnerability in nltk.featstruct.FeatStructReader that allows unauthenticated attackers to cause a denial of service by supplying deeply nested feature-structure input. Attackers can craft trivial payloads with nested brackets that exceed Python's recursion limit and raise an unhandled RecursionError, crashing applications that parse user-supplied feature structures or feature grammars.

CVSS Base Scores

version 3.1