0.0
NA
CVE-2026-29975
LwJSON Denial of Service through Improper Input Validation
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.

INFO

Published Date :

May 8, 2026, 4:16 p.m.

Last Modified :

May 8, 2026, 4:16 p.m.

Remotely Exploit :

No
Affected Products

The following products are affected by CVE-2026-29975 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

Solution
Update lwjson to a version that corrects streaming JSON parser input validation issues.
  • Update to a fixed version of lwjson.
  • Review and apply relevant patches.
  • Validate input handling logic.
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-29975.

URL Resource
https://gist.github.com/dwilliams27/b99fd41be5d6848691797042cbfc1103
https://github.com/MaJerle/lwjson/blob/develop/lwjson/src/lwjson/lwjson_stream.c#L362-L364
https://github.com/MaJerle/lwjson/tree/develop
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-29975 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-29975 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-29975 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-29975 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    May. 08, 2026

    Action Type Old Value New Value
    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.
    Added Reference https://gist.github.com/dwilliams27/b99fd41be5d6848691797042cbfc1103
    Added Reference https://github.com/MaJerle/lwjson/blob/develop/lwjson/src/lwjson/lwjson_stream.c#L362-L364
    Added Reference https://github.com/MaJerle/lwjson/tree/develop
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.