Fluid Attacks Database

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.

Mitigation

Update Impact

Minimal update. May introduce new vulnerabilities or breaking changes.

Ecosystem	Component	Affected version	Patched versions
debian 11	nltk	=3.10.0-1 \|\| =3.10.1-1 \|\| =3.10.3-1 \|\| =3.5-1 \|\| =3.6.5-1 \|\| =3.6.7-1 \|\| =3.7-1 \|\| =3.8-1 \|\| =3.8.1-1 \|\| =3.9.1-1 \|\| =3.9.1-2 \|\| =3.9.2-1 \|\| =3.9.3-1	-
debian 12	nltk	=3.10.0-1 \|\| =3.10.1-1 \|\| =3.10.3-1 \|\| =3.8-1 \|\| =3.8.1-1 \|\| =3.9.1-1 \|\| =3.9.1-2 \|\| =3.9.2-1 \|\| =3.9.3-1	-
debian 13	nltk	=3.10.0-1 \|\| =3.10.1-1 \|\| =3.10.3-1 \|\| =3.9.1-2 \|\| =3.9.2-1 \|\| =3.9.3-1	-
debian 14	nltk	=3.10.0-1 \|\| =3.10.1-1 \|\| =3.9.1-2 \|\| =3.9.2-1 \|\| =3.9.3-1 \|\| >=0 <3.10.3-1	3.10.3-1

Aliases

1. CVE-2026-817242. NVD-2026-817243. OSV-DEBIAN-2026-817244. OSV-2026-817245. SECURITY-TRACKER-CVE-2026-81724

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