CVE-2026-67215 cJSON JSON Patch copy/add Uncontrolled Recursion Stack Exhaustion

High 8.7 Published 29 Jul 2026 Updated 29 Jul 2026

An attacker can crash the application by supplying a malicious JSON Patch that causes uncontrolled recursion and stack exhaustion in the cJSON library.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Over the internet
Victim action needed: Not needed
Fix: Available

What is CVE-2026-67215?

CVE-2026-67215 is a high-severity denial of service vulnerability in DaveGamble cJSON, published on 29 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

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.

Weakness: CWE-674

Which versions are affected by CVE-2026-67215?

It affects 1 product.

Products include Davegamble Cjson.

How do I fix CVE-2026-67215?

Upgrade to a fixed version.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2026-67215 being exploited?

There is no known exploitation of CVE-2026-67215 in the wild and no public exploit code.

Sources

Also known as AZL-94410, AZL-94437, DEBIAN-CVE-2026-67215, ECHO-29ef-6520-8114, GHSA-5q3m-r3x7-8phg, ROOT-OS-ALPINE-321-CVE-2026-67215 and 2 more.