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 12, 2026, 2:51 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
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
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | 134c704f-9b21-4f2e-91b3-4a467353bcc0 |
Solution
- 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.
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.
-
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
May. 08, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Added CWE CWE-835 Added Reference https://gist.github.com/dwilliams27/b99fd41be5d6848691797042cbfc1103 -
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