# CVE-2026-67217

## Summary

- **CVE ID:** CVE-2026-67217
- **Severity:** MEDIUM
- **CVSS Score:** 6.9 (CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N)
- **CWE:** CWE-696, CWE-696
- **Published:** Jul 29, 2026
- **Last Modified:** Jul 29, 2026

## 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.

## Affected Products

- DaveGamble — cJSON (0)

## References

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

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.30%
- **EPSS Percentile:** 22.2

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-11._