CVE-2026-40504 Creolabs Gravity < 0.9.6 Heap Buffer Overflow via gravity_vm_exec
Attackers can achieve arbitrary code execution by crafting scripts with many string literals, exploiting a heap buffer overflow in the Gravity VM.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-40504?
CVE-2026-40504 is a critical memory corruption vulnerability in marcobambini gravity, published on 16 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Creolabs Gravity before 0.9.6 contains a heap buffer overflow vulnerability in the gravity_vm_exec function that allows attackers to write out-of-bounds memory by crafting scripts with many string literals at global scope. Attackers can exploit insufficient bounds checking in gravity_fiber_reassign() to corrupt heap metadata and achieve arbitrary code execution in applications that evaluate untrusted scripts.
Weakness: CWE-122
Which versions are affected by CVE-2026-40504?
How do I fix CVE-2026-40504?
No fix has been published for CVE-2026-40504 yet. Limit exposure of the affected software until one is available.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-40504 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-40504 exists.
Sources
Also known as GHSA-3r49-76f3-pf2m.