CVE-2026-81724
MEDIUM
NVD
CVSS Score
5.3
Severity
MEDIUM
Published
Aug 27, 2026
Vendor
unknown
Description
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.