CVE-2021-4136 Heap-based Buffer Overflow in vim/vim

High 7.3 Published 19 Dec 2021 Updated 8 Oct 2026

A heap-based buffer overflow in Vim allows attackers to execute arbitrary code or cause a denial of service via crafted input.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Local or same network only
Victim action needed: A user has to click or open something
Fix: Available

What is CVE-2021-4136?

CVE-2021-4136 is a high-severity memory corruption vulnerability in Apple Mac Os X, published on 19 Dec 2021. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

Official description

vim is vulnerable to Heap-based Buffer Overflow

Weakness: CWE-787, CWE-122

Which versions are affected by CVE-2021-4136?

It affects 4 products.

Products include Apple Mac Os X, Apple Macos, Fedoraproject Fedora, Vim Vim.

How do I fix CVE-2021-4136?

Apply the vendor's patch.

Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.

Is CVE-2021-4136 being exploited?

There is no known exploitation of CVE-2021-4136 in the wild and no public exploit code.

All Apple Mac Os X vulnerabilities

Sources

Also known as ALPINE-CVE-2021-4136, AZL-7057, DEBIAN-CVE-2021-4136, GHSA-85p4-xh3v-w37r.