PT-2026-65814 · Dave Gamble · Cjson

CVE-2026-67216 · Published 2026-07-29 · Updated 2026-07-29

NVD

CVSS v3.1

5.9

Medium

Base vector

AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

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.

Exploit

Fix

Weakness Enumeration

CWE-407

Related Identifiers

CVE-2026-67216

Affected Products

Cjson

References · 4

• 🔥 https://joshua.hu/cjson-json-parser-cve-vulnerabilities · Exploit
• https://nvd.nist.gov/vuln/detail/CVE-2026-67216 · Security Note
• https://github.com/DaveGamble/cJSON/blob/v1.7.19/cJSON.c#L3057-L3180 · Note
• https://vulncheck.com/advisories/cjson-cjson-compare-exponential-complexity-denial-of-service · Note