CVE-2026-29975

Infinite Loop in lwjson Streaming Parser Causing Denial of Service

Published May 8, 2026 CVSS 3.1 · 7.5 High EPSS < 1% KEV · Not listed
Description
lwjson 1.8.1 contains an improper input validation vulnerability in the streaming JSON parser (lwjson_stream.c). The end-of-string detection logic incorrectly identifies escaped quote characters by only checking the immediately preceding character rather than counting consecutive backslashes, causing valid JSON strings ending with an escaped backslash (like "\\") to never terminate parsing. A remote attacker can send well-formed JSON to cause applications using lwjson_stream_parse() to hang indefinitely, resulting in denial of service.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
First Time appeared Majerle
Majerle lwjson
Vendors & Products Majerle
Majerle lwjson
Type Values Removed Values Added
Title Infinite Loop in lwjson Streaming Parser Causing Denial of Service
Type Values Removed Values Added
Title Improper String Parsing Leads to Application Hang in lwjson Streaming Parser
Weaknesses CWE-679
Type Values Removed Values Added
Title Improper String Parsing Leads to Application Hang in lwjson Streaming Parser
Weaknesses CWE-679
Type Values Removed Values Added
Weaknesses CWE-835
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}

ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description lwjson 1.8.1 contains an improper input validation vulnerability in the streaming JSON parser (lwjson_stream.c). The end-of-string detection logic incorrectly identifies escaped quote characters by only checking the immediately preceding character rather than counting consecutive backslashes, causing valid JSON strings ending with an escaped backslash (like "\\") to never terminate parsing. A remote attacker can send well-formed JSON to cause applications using lwjson_stream_parse() to hang indefinitely, resulting in denial of service.
References
Weaknesses

Sources

Status
PUBLISHED
Assigner
mitre
Published
Updated
May 8, 2026, 6:07 PM
Reserved
Mar 4, 2026, 12:00 AM
Status
Deferred
Published
May 8, 2026, 4:16 PM
Modified
Jun 17, 2026, 10:29 AM