CVE-2024-27934: Deno

High severity, CVSS 8.8. EPSS: 0.4% chance of exploitation in the next 30 days.

Deno is a JavaScript, TypeScript, and WebAssembly runtime. Starting in version 1.36.2 and prior to version 1.40.3, use of inherently unsafe `*const c_void` and `ExternalPointer` leads to use-after-free access of the underlying structure, resulting in arbitrary code execution. Use of inherently unsafe `*const c_void` and `ExternalPointer` leads to use-after-free access of the underlying structure, which is exploitable by an attacker controlling the code executed inside a Deno runtime to obtain arbitrary code execution on the host machine regardless of permissions. This bug is known to be exploitable for both `*const c_void` and `ExternalPointer` implementations. Version 1.40.3 fixes this issue.

Affected products

• Deno Deno: from 1.36.2, before 1.40.3 (fixed in 1.40.3)

Published 2024-03-21. Last modified 2026-06-17.