CVE-2026-67217

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.

CVSS 4.0

6.9CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N

CVSS 3.1

5.3CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

EPSS

0.4% chance of exploitation in the next 30 days; higher than 37% of CVEs (scores of 2026-10-25)

CWE

CWE-696

Published

2026-07-29

Modified

2026-10-23

Record from

the NVD, synced 2026-10-24

Affected

• davegamble:cjson

References

• https://github.com/DaveGamble/cJSON/blob/v1.7.19/cJSON_Utils.c#L887-L948
• https://joshua.hu/cjson-json-parser-cve-vulnerabilities
• https://www.vulncheck.com/advisories/cjson-json-patch-non-atomic-application-destroys-data-before-validation
• https://joshua.hu/cjson-json-parser-cve-vulnerabilities

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