CVE-2026-67217
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…
Does this matter?
Lower severity and a low EPSS score (0.30%). Track it; it rarely justifies an emergency change on its own.
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.
- CVSS 4.0
- 6.9 MEDIUMCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
- EPSS
- 0.30% probability · 22th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-696
- Affected
- davegamble/cjson
- Source
- disclosure@vulncheck.com
References
- https://github.com/DaveGamble/cJSON/blob/v1.7.19/cJSON_Utils.c#L887-L948Patch
- https://joshua.hu/cjson-json-parser-cve-vulnerabilitiesExploit, Press/Media Coverage, Third Party Advisory
- https://www.vulncheck.com/advisories/cjson-json-patch-non-atomic-application-destroys-data-before-validationThird Party Advisory
- https://joshua.hu/cjson-json-parser-cve-vulnerabilitiesExploit, Press/Media Coverage, Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.