CVEvulnerability
CVE-2026-81724
6.9 MEDIUM
Official page ↗
- Status
- Analyzed
- Published
- 2026-08-27
- Last modified
- 2026-08-31
- Assigner
- [email protected]
- CVSS 4.0 ([email protected])
- 6.9 MEDIUM — CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
- CVSS 3.1 ([email protected])
- 5.3 MEDIUM — CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
- Weaknesses
- CWE-674
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.
Affected configurations
• nltk nltk (< 3.10.3)
Related
Weakness · CWE (1)
- CWE-674 Uncontrolled Recursion weakness
References
- https://github.com/nltk/nltk/security/advisories/GHSA-cw6x-m8jw-qmrh Exploit, Vendor Advisory
- https://www.vulncheck.com/advisories/nltk-before-3.10.3-denial-of-service-via-uncontrolled-recursion Third Party Advisory
- https://github.com/nltk/nltk/security/advisories/GHSA-cw6x-m8jw-qmrh Exploit, Vendor Advisory