Vulnerability in Davegamble Cjson

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.

EPSS: 0.004 (36.0th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.9 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-67216?
CVE-2026-67216 is a medium-severity vulnerability in Davegamble Cjson, classified under Inefficient Algorithmic Complexity. CVSS score: 5.9/10. Published 2026-07-29.
How severe is CVE-2026-67216?
Medium severity. CVSS v3 base score is 5.9 out of 10.