CVE-2024-27934: *const c_void / ExternalPointer unsoundness leading to use-after-free

Severity: high (CVSS 8.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2024-03-21 · updated 2026-06-17
Weakness: CWE-416

Description

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

denoland deno: from 1.36.2 before 1.40.3 — fixed in 1.40.3

How to fix

Upgrade to a fixed version: denoland deno 1.40.3. Check the vendor advisory for mitigations.

References

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