CVE-2026-67217: davegamble cjson Incorrect Behavior Order

Vulnerability summary

CVE-2026-67217 is a medium (CVSS 6.9) Incorrect Behavior Order vulnerability in davegamble cjson. EPSS estimates a 0.43% chance of exploitation in the next 30 days, higher than 36.2% of scored vulnerabilities. 1 public exploit is recorded.

Timeline

1. 29-07-2026
   PublishedVulnerability first disclosed.
2. 29-07-2026
   Last modifiedVulnerability information updated.

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.

• CWE-696Incorrect Behavior OrderThe product performs multiple related behaviors, but the behaviors are performed in the wrong order in ways that may produce resultant weaknesses.