CVE-2026-67216: high-severity vulnerability in DaveGamble cJSON
cJSON cJSON_Compare Exponential Complexity Denial of Service
Published · Updated
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41Vexday Risk Score
No sign of exploitation. It has a public proof of concept.
ssvc Attendcvss 8.2epss 0.6%
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:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
Affected products
DaveGamble · cJSONpublic PoCs found — 1
cve_referencejoshua.hu/cjson-json-parser-cve-vulnerabilitiesunverified⚠ Public resources, to assess the exposure of systems you control or are authorized to test. Test only with authorization.
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