Vulnerability · Published Jul 29, 2026 · Assigned by VulnCheck
CVE-2026-67215cJSON JSON Patch copy/add Uncontrolled Recursion Stack Exhaustion
High 7.5
In plain English
A high-severity security flaw in cJSON from DaveGamble. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.7% (higher than 53% of all known vulnerabilities).
Official 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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | cjson | no fix listed | DEBIAN-CVE-2026-67215 |
| Debian:13 | cjson | no fix listed | DEBIAN-CVE-2026-67215 |
| Debian:14 | cjson | no fix listed | DEBIAN-CVE-2026-67215 |
| Ubuntu:26.04:LTS | cjson | no fix listed | UBUNTU-CVE-2026-67215 |
| Ubuntu:26.10 | cjson | no fix listed | UBUNTU-CVE-2026-67215 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| DaveGamble | cJSON | 0 – through 1.7.19 |
Weakness: CWE-674 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
References
- Security vulnerabilities in the cJSON JSON parser (Joshua Rogers) exploit
- cJSON_Delete unbounded recursion (cJSON.c) technical-description
- apply_patch copy/add duplicate-and-graft (cJSON_Utils.c) technical-description
- VulnCheck Advisory: cJSON JSON Patch copy/add Uncontrolled Recursion Stack Exhaustion third-party-advisory