DaveGamble cJSON up to 1.7.19 cJSON_Utils.c cJSONUtils_MergePatch use after free

CVSS Meta Temp Score
CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.
Current Exploit Price (≈)
Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.
CTI Interest Score
Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
6.6$0-$5k0.93+

Summaryinfo

A vulnerability, which was classified as critical, has been found in DaveGamble cJSON up to 1.7.19. The impacted element is the function cJSONUtils_MergePatch of the file cJSON_Utils.c. This manipulation causes use after free. This vulnerability is registered as CVE-2026-87933. Remote exploitation of the attack is possible. Furthermore, an exploit is available. The pull request to fix this issue awaits acceptance.

Detailsinfo

A vulnerability classified as critical was found in DaveGamble cJSON up to 1.7.19. Affected by this vulnerability is the function cJSONUtils_MergePatch of the file cJSON_Utils.c. The manipulation with an unknown input leads to a use after free vulnerability. The CWE definition for the vulnerability is CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. As an impact it is known to affect confidentiality, integrity, and availability.

It is possible to read the advisory at github.com. This vulnerability is known as CVE-2026-87933. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. Technical details and also a public exploit are known.

It is possible to download the exploit at github.com. It is declared as proof-of-concept. The pull request to fix this issue awaits acceptance.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

Vendor

Name

Version

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.3
VulDB Meta Temp Score: 6.6

VulDB Base Score: 7.3
VulDB Temp Score: 6.6
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
💳💳💳💳💳💳
💳💳💳💳💳💳
💳💳💳💳💳💳
VectorComplexityAuthenticationConfidentialityIntegrityAvailability
UnlockUnlockUnlockUnlockUnlockUnlock
UnlockUnlockUnlockUnlockUnlockUnlock
UnlockUnlockUnlockUnlockUnlockUnlock

VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Use after free
CWE: CWE-416 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Access: Public
Status: Proof-of-Concept
Download: 🔒
Price Prediction: 🔍
Current Price Estimation: 🔒

0-DayUnlockUnlockUnlockUnlock
TodayUnlockUnlockUnlockUnlock

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: no mitigation known
Status: 🔍

0-Day Time: 🔒

Timelineinfo

09/09/2026 Advisory disclosed
09/09/2026 +0 days VulDB entry created
09/09/2026 +0 days VulDB entry last update

Sourcesinfo

Product: github.com

Advisory: 1060
Status: Not defined
Confirmation: 🔒

CVE: CVE-2026-87933 (🔒)
GCVE (CVE): GCVE-0-2026-87933
GCVE (VulDB): GCVE-100-401815
scip Labs: https://www.scip.ch/en/?labs.20161013

Entryinfo

Created: 09/09/2026 18:26
Changes: 09/09/2026 18:26 (58)
Complete: 🔍
Submitter: lrrh
Cache ID: 216::103

Submitinfo

Accepted

Be aware that VulDB is the high quality source for vulnerability data.

Discussion

No comments yet. Languages: en.

Please log in to comment.

◂ PreviousOverviewNext ▸

Do you want to use VulDB in your project?

Use the official API to access entries easily!