CVE-2026-67215

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.

CVSS 4.0

8.7CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

CVSS 3.1

7.5CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS

0.7% chance of exploitation in the next 30 days; higher than 52% of CVEs (scores of 2026-10-25)

CWE

CWE-674

Published

2026-07-29

Modified

2026-10-23

Record from

the NVD, synced 2026-10-24

Affected

• davegamble:cjson

References

• https://github.com/DaveGamble/cJSON/blob/v1.7.19/cJSON.c#L253-L261
• https://github.com/DaveGamble/cJSON/blob/v1.7.19/cJSON_Utils.c#L906-L940
• https://joshua.hu/cjson-json-parser-cve-vulnerabilities
• https://www.vulncheck.com/advisories/cjson-json-patch-copy-add-uncontrolled-recursion-stack-exhaustion
• https://joshua.hu/cjson-json-parser-cve-vulnerabilities

Check your stackJSON