Vulnerability · Published Apr 16, 2026 · Assigned by VulnCheck

CVE-2026-40504Creolabs Gravity < 0.9.6 Heap Buffer Overflow via gravity_vm_exec

Critical 9.8

In plain English

A critical-severity heap buffer overflow in gravity from marcobambini. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.6% (higher than 51% of all known vulnerabilities).

Severity (CVSS 3.1)9.8Critical

Exploit odds (30 days)0.6%top 49.1% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

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.

Affected products (as reported)

Vendor	Product	Versions
marcobambini	gravity	0 – before 0.9.60 – before 18b9195598d9b944376754c6d1ad76e38a4adca1

Weakness: CWE-122 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

References

https://github.com/marcobambini/gravity/releases/tag/0.9.6 release-notes
https://github.com/marcobambini/gravity/issues/437 issue-tracking
https://github.com/marcobambini/gravity/commit/18b9195598d9b944376754c6d1ad76e38a4adca1 patch
https://www.vulncheck.com/advisories/creolabs-gravity-heap-buffer-overflow-via-gravity-vm-exec third-party-advisory