Published: August 22, 2026 | Last Modified: August 22, 2026
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.
This analysis is generated by Ghostwire from NVD, CISA KEV, EPSS, and open-source intelligence data. Verify findings through primary sources before acting.