apply_patch delete-before-validate ordering (cJSON_Utils.c)Technical description
https://github.com/DaveGamble/cJSON/blob/v1.7.19/cJSON_Utils.c CVE-2026-67217
MEDIUM
cJSON JSON Patch Non-Atomic Application Destroys Data Before Validation
Record summary
CVE-2026-67217 has a selected CVSS score of 6.9 (medium).
Description
cJSON through 1.7.19 applies RFC 6902 JSON Patch operations non-atomically in apply_patch() in cJSON_Utils.c. For a replace operation that is missing its value member, or a move operation whose destination path cannot be resolved, the existing target member is detached and deleted before the operation is fully validated, so the target document is mutated while cJSONUtils_ApplyPatches() or cJSONUtils_ApplyPatchesCaseSensitive() returns a failure status. An attacker who can supply the patch document can destroy addressable members of the target document even though the API reports that the patch failed, defeating the all-or-nothing behavior callers rely on to reject bad patches.
Description source: CVE List
Exploitation context
CISA SSVC decision
ExploitationPoC
AutomatableYes
Technical impactPartial
CISA Coordinator · SSVC 2.0.3 · Evaluated Jul 29, 2026 · Source: CVE List
Affected products and versions
1| Product | Source | Version range | Status |
|---|---|---|---|
Default status: affected | CVE List | Through 1.7.19 | affected |
References
4Security vulnerabilities in the cJSON JSON parser (Joshua Rogers)exploit
https://joshua.hu/cjson-json-parser-cve-vulnerabilities nvd.nist.gov
https://nvd.nist.gov/vuln/detail/CVE-2026-67217 VulnCheck Advisory: cJSON JSON Patch Non-Atomic Application Destroys Data Before ValidationThird-party advisory
https://www.vulncheck.com/advisories/cjson-json-patch-non-atomic-application-destroys-data-before-validation