Shodan
Vulnerabilities
Vulnerable Software

Vulnerability Details CVE-2026-66393

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.
Exploit prediction scoring system (EPSS) score
EPSS Score 0.004
EPSS Ranking 29.1%
CVSS Severity
CVSS v3 Score 7.5
Products affected by CVE-2026-66393
  • Nltk » Nltk » Version: 2.0.1
    cpe:2.3:a:nltk:nltk:2.0.1
  • Nltk » Nltk » Version: 2.0.3
    cpe:2.3:a:nltk:nltk:2.0.3
  • Nltk » Nltk » Version: 2.0.4
    cpe:2.3:a:nltk:nltk:2.0.4
  • Nltk » Nltk » Version: 3.0.0
    cpe:2.3:a:nltk:nltk:3.0.0
  • Nltk » Nltk » Version: 3.0.1
    cpe:2.3:a:nltk:nltk:3.0.1
  • Nltk » Nltk » Version: 3.0.2
    cpe:2.3:a:nltk:nltk:3.0.2
  • Nltk » Nltk » Version: 3.0.3
    cpe:2.3:a:nltk:nltk:3.0.3
  • Nltk » Nltk » Version: 3.0.4
    cpe:2.3:a:nltk:nltk:3.0.4
  • Nltk » Nltk » Version: 3.0.5
    cpe:2.3:a:nltk:nltk:3.0.5
  • Nltk » Nltk » Version: 3.1
    cpe:2.3:a:nltk:nltk:3.1
  • Nltk » Nltk » Version: 3.2
    cpe:2.3:a:nltk:nltk:3.2
  • Nltk » Nltk » Version: 3.2.1
    cpe:2.3:a:nltk:nltk:3.2.1
  • Nltk » Nltk » Version: 3.2.2
    cpe:2.3:a:nltk:nltk:3.2.2
  • Nltk » Nltk » Version: 3.2.3
    cpe:2.3:a:nltk:nltk:3.2.3
  • Nltk » Nltk » Version: 3.2.4
    cpe:2.3:a:nltk:nltk:3.2.4
  • Nltk » Nltk » Version: 3.2.5
    cpe:2.3:a:nltk:nltk:3.2.5
  • Nltk » Nltk » Version: 3.3
    cpe:2.3:a:nltk:nltk:3.3
  • Nltk » Nltk » Version: 3.4
    cpe:2.3:a:nltk:nltk:3.4
  • Nltk » Nltk » Version: 3.4.1
    cpe:2.3:a:nltk:nltk:3.4.1
  • Nltk » Nltk » Version: 3.4.3
    cpe:2.3:a:nltk:nltk:3.4.3
  • Nltk » Nltk » Version: 3.4.4
    cpe:2.3:a:nltk:nltk:3.4.4
  • Nltk » Nltk » Version: 3.4.5
    cpe:2.3:a:nltk:nltk:3.4.5
  • Nltk » Nltk » Version: 3.5
    cpe:2.3:a:nltk:nltk:3.5
  • Nltk » Nltk » Version: 3.6
    cpe:2.3:a:nltk:nltk:3.6
  • Nltk » Nltk » Version: 3.6.1
    cpe:2.3:a:nltk:nltk:3.6.1
  • Nltk » Nltk » Version: 3.6.2
    cpe:2.3:a:nltk:nltk:3.6.2
  • Nltk » Nltk » Version: 3.6.3
    cpe:2.3:a:nltk:nltk:3.6.3
  • Nltk » Nltk » Version: 3.6.4
    cpe:2.3:a:nltk:nltk:3.6.4
  • Nltk » Nltk » Version: 3.6.5
    cpe:2.3:a:nltk:nltk:3.6.5
  • Nltk » Nltk » Version: 3.6.6
    cpe:2.3:a:nltk:nltk:3.6.6
  • Nltk » Nltk » Version: 3.6.7
    cpe:2.3:a:nltk:nltk:3.6.7
  • Nltk » Nltk » Version: 3.7
    cpe:2.3:a:nltk:nltk:3.7
  • Nltk » Nltk » Version: 3.8
    cpe:2.3:a:nltk:nltk:3.8
  • Nltk » Nltk » Version: 3.8.1
    cpe:2.3:a:nltk:nltk:3.8.1
  • Nltk » Nltk » Version: 3.9
    cpe:2.3:a:nltk:nltk:3.9
  • Nltk » Nltk » Version: 3.9.1
    cpe:2.3:a:nltk:nltk:3.9.1
  • Nltk » Nltk » Version: 3.9.2
    cpe:2.3:a:nltk:nltk:3.9.2
  • Nltk » Nltk » Version: 3.9.3
    cpe:2.3:a:nltk:nltk:3.9.3


Products
Pricing
Contact Us

Shodan ® - All rights reserved