CVE-2026-5186 Nothings stb Multi-frame GIF File stb_image.h stbi__load_gif_main double free
A double free vulnerability in the stb image library's GIF handler allows local attackers to potentially execute code or cause denial of service.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-5186?
CVE-2026-5186 is a medium-severity use after free vulnerability in Nothings stb, published on 31 Mar 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
A weakness has been identified in Nothings stb up to 2.30. This impacts the function stbi__load_gif_main of the file stb_image.h of the component Multi-frame GIF File Handler. This manipulation causes double free. The attack requires local access. The exploit has been made available to the public and could be used for attacks. The vendor was contacted early about this disclosure but did not respond in any way.
Which versions are affected by CVE-2026-5186?
How do I fix CVE-2026-5186?
No fix has been published for CVE-2026-5186 yet. Limit exposure of the affected software until one is available.
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-2026-5186 being exploited?
There is no known exploitation of CVE-2026-5186 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-5186, DEBIAN-CVE-2026-5186, GHSA-593x-hf83-hmrv, UBUNTU-CVE-2026-5186.