Upstream information

CVE-2026-66393 at MITRE

Description

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.

SUSE information

Overall state of this security issue: Does not affect SUSE products

This issue is currently rated as having important severity.

CVSS v3 Scores
CVSS detail CNA (VulnCheck) SUSE
Base Score 7.5 7.5
Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack Vector Network Network
Attack Complexity Low Low
Privileges Required None None
User Interaction None None
Scope Unchanged Unchanged
Confidentiality Impact None None
Integrity Impact None None
Availability Impact High High
CVSSv3 Version 3.1 3.1
CVSS v4 Scores
CVSS detail CNA (VulnCheck) SUSE
Base Score 8.7 8.7
Vector CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/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:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/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
Attack Vector Network Network
Attack Complexity Low Low
Attack Requirements None None
Privileges Required None None
User Interaction None None
Vulnerable System Confidentiality Impact None None
Vulnerable System Integrity Impact None None
Vulnerable System Availability Impact High High
Subsequent System Confidentiality Impact None None
Subsequent System Integrity Impact None None
Subsequent System Availability Impact None None
CVSSv4 Version 4.0 4.0
SUSE Bugzilla entry: 1277504 [IN_PROGRESS]

No SUSE Security Announcements cross referenced.

SUSE Timeline for this CVE

CVE page created: Mon Aug 31 11:37:44 2026
CVE page last modified: Mon Sep 28 17:41:29 2026