CVE-2026-67216
highpriority · track · 30EPSS 0.006 · 51 %ileEURUUSEPSS · scored 2026-10-25
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
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 4.6–8.2
ssvc
A stakeholder decision — act, attend, or track — from exploitation and impact.
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (3)
Products and version ranges known to be affected.
also known as (4)
Other names and identifiers for this entity.
sources
Which sources assert this record, and when.
references (9)
External citations — patches, advisories, analysis.
- https://github.com/DaveGamble/cJSON/blob/v1.7.19/cJSON.c#L3057-L3180cnnvd
- https://joshua.hu/cjson-json-parser-cve-vulnerabilitiescnnvd
- https://www.vulncheck.com/advisories/cjson-cjson-compare-exponential-complexity-denial-of-servicecnnvd
- https://github.com/DaveGamble/cJSON/blob/v1.7.19/cJSON.c#L3057-L3180enisa_euvd
- https://joshua.hu/cjson-json-parser-cve-vulnerabilitiesenisa_euvd
- https://www.vulncheck.com/advisories/cjson-cjson-compare-exponential-complexity-denial-of-serviceenisa_euvd
- https://github.com/DaveGamble/cJSON/blob/v1.7.19/cJSON.c#L3057-L3180Patchnvd
- https://joshua.hu/cjson-json-parser-cve-vulnerabilitiesExploitPress/Media CoverageThird Party Advisorynvd
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