CVE-2026-67217

cJSON JSON Patch Non-Atomic Application Destroys Data Before Validation

MEDIUM
5.3
CVSS Score
Published: July 29, 2026 at 01:32 PM UTC
Updated: October 23, 2026 at 11:10 PM UTC
1 product affected across 1 vendorcJSON

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Severity
MEDIUM5.3
Exploit prediction
EPSS 0.4%
SSVC
PoC

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

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

All versionsv ≤ 1.7.19

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (3)

SSVC — Action Prioritization

SSVCPoCAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

5.3MEDIUMVulnCheck
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
LOW
Availability
NONE
Vector?

Quick Info

StatusANALYZED
CWE
CWE-696

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