CVE-2026-29975

lwjson 1.8.1 contains an improper input validation vulnerability in the streaming JSON parser (lwjson_stream.c)

High · published May 8, 2026

CVSS v3.1
7.5
EPSS
1%
Percentile
54.5
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
7.5 · HIGH
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS v4.0
Not supplied
EPSS
0.00750 · 54.5th percentile
Published
2026-05-08T00:00Z
EPSS history
Timeline
  • 08 MAY 00:00Z
    lwjson 1.8.1 contains an improper input validation vulnerability in the streaming JSON parser (lwjson_stream.c)
    cvelistv5