Description
cJSON through 1.7.19 is vulnerable to uncontrolled recursion leading to stack exhaustion when an untrusted RFC 6902 JSON Patch is applied via cJSONUtils_ApplyPatches() or cJSONUtils_ApplyPatchesCaseSensitive(). A patch containing add and copy operations grafts duplicated subtrees to amplify document depth beyond the parser's nesting limit: cJSON_Delete() recurses with no depth bound, and the cJSON_Duplicate() guard CJSON_CIRCULAR_LIMIT is set to 10000, ten times the parser's 1000-level nesting limit and high enough to overflow a default thread stack. An attacker who can supply the patch document can crash the process, resulting in denial of service.
Metrics
CVSS 3.1 7.5/10
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HWeakness enumeration
Affected software
| Vendor | Product | Versions |
|---|---|---|
| DaveGamble | cJSON | <= 1.7.19 |
References
- https://github.com/DaveGamble/cJSON/blob/v1.7.19/cJSON.c#L253-L261Patch
- https://github.com/DaveGamble/cJSON/blob/v1.7.19/cJSON_Utils.c#L906-L940Patch
- https://joshua.hu/cjson-json-parser-cve-vulnerabilitiesExploit, Press/Media Coverage, Third Party Advisory
- https://www.vulncheck.com/advisories/cjson-json-patch-copy-add-uncontrolled-recursion-stack-exhaustionThird Party Advisory
- https://joshua.hu/cjson-json-parser-cve-vulnerabilitiesExploit, Press/Media Coverage, Third Party Advisory
Timeline
- Published
- Jul 29, 2026
- Last modified
- Oct 23, 2026
- NVD status
- Analyzed