CVE-2026-87933 DaveGamble cJSON cJSON_Utils.c cJSONUtils_MergePatch use after free
A use-after-free vulnerability in cJSON's MergePatch function allows remote attackers to potentially execute code or cause denial of service.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-87933?
CVE-2026-87933 is a medium-severity use after free vulnerability in DaveGamble cJSON, published on 10 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
A vulnerability was found in DaveGamble cJSON up to 1.7.19. The affected element is the function cJSONUtils_MergePatch of the file cJSON_Utils.c. The manipulation results in use after free. The attack may be launched remotely. The exploit has been made public and could be used. The pull request to fix this issue awaits acceptance.
Which versions are affected by CVE-2026-87933?
How do I fix CVE-2026-87933?
Apply the vendor's patch.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2026-87933 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-87933 exists.
Sources
Also known as AZL-100911, DEBIAN-CVE-2026-87933, ECHO-bdd3-ee8d-c65f, GHSA-7jcg-95pj-h5fp, UBUNTU-CVE-2026-87933.