CVE-2026-81724 — NLTK before 3.10.3 Denial of Service via Uncontrolled Recursion
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 sup…
Published: 2026-08-27 · CVSS: 6.9 · CVSS 4.0
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.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7