GHSA-rf74-v2fm-23pw: Natural Language Toolkit (NLTK) has unbounded recursion in JSONTaggedDecoder.decode_obj() may cause DoS
(updated )
JSONTaggedDecoder.decode_obj() in nltk/jsontags.py calls itself
recursively without any depth limit. A deeply nested JSON structure
exceeding sys.getrecursionlimit() (default: 1000) will raise an
unhandled RecursionError, crashing the Python process.
References
- github.com/advisories/GHSA-rf74-v2fm-23pw
- github.com/nltk/nltk/commit/00cdcd392142e6c745e7120c8d50a24127df5fad
- github.com/nltk/nltk/security/advisories/GHSA-rf74-v2fm-23pw
- github.com/pypa/advisory-database/tree/main/vulns/nltk/PYSEC-2026-3724.yaml
- nvd.nist.gov/vuln/detail/CVE-2026-66393
- www.vulncheck.com/advisories/nltk-before-denial-of-service-via-jsontaggeddecoder
Code Behaviors & Features
Detect and mitigate GHSA-rf74-v2fm-23pw with GitLab Dependency Scanning
Secure your software supply chain by verifying that all open source dependencies used in your projects contain no disclosed vulnerabilities. Dependency Scanning using SBOM also detects vulnerabilities from proprietary advisories that this site does not include. Learn more about Dependency Scanning using SBOM →