CVE-2026-67216

cJSON through 1.7.19 contains an inefficient algorithmic complexity flaw in cJSON_Compare(). When comparing objects, the function recurses into each shared subtree twice, once in each direction, with no depth guard, making the running time exponential in nesting depth. A small, deeply nested document of a few hundred bytes (depth around 40) compared for equality consumes hours of CPU, and the cost roughly doubles with each additional level of nesting. An application that calls cJSON_Compare() on attacker-influenced JSON that is structurally equal to a reference document is exposed to a denial-of-service condition.

CVSS v3 5.9 MEDIUM

5.9^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 2.2 / Impact : 3.6

Attack Vector NETWORK

Attack Complexity HIGH

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://github.com/DaveGamble/cJSON/blob/v1.7.19/cJSON.c#L3057-L3180	Patch
https://joshua.hu/cjson-json-parser-cve-vulnerabilities	Exploit Press/Media Coverage Third Party Advisory
https://www.vulncheck.com/advisories/cjson-cjson-compare-exponential-complexity-denial-of-service	Third Party Advisory

Configurations

Configuration 1 (hide)

cpe:2.3:a:davegamble:cjson:*:*:*:*:*:*:*:*

History

No history.

Information

Published : 2026-07-29 14:16

Updated : 2026-08-04 15:05

NVD link : CVE-2026-67216

Mitre link : CVE-2026-67216

CVE.ORG link : CVE-2026-67216

JSON object : View

Products Affected

davegamble

cjson

CWE

CWE-407

Inefficient Algorithmic Complexity

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