CVE-2026-40504

CVE-2026-40504 is a critical-severity vulnerability with a CVSS 3.x base score of 9.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-122.

Key facts

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.

Frequently asked questions

What is CVE-2026-40504?
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.
How severe is CVE-2026-40504?
CVE-2026-40504 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-40504 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (46th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-40504?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
Does CVE-2026-40504 have an EU (EUVD) identifier?
Yes. CVE-2026-40504 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-23145.
When was CVE-2026-40504 published?
CVE-2026-40504 was published on 2026-04-16 and last updated on 2026-06-17.

References

Other CWE-122 (Heap-based Buffer Overflow) vulnerabilities

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