CVE-2020-36557 Use after free in n/a

What is CVE-2020-36557?

CVE-2020-36557 is a medium-severity use after free vulnerability in Linux kernel, published on 21 Jul 2022. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

A race condition in the Linux kernel before 5.6.2 between the VT_DISALLOCATE ioctl and closing/opening of ttys could lead to a use-after-free.

Weakness: CWE-416, CWE-362

Which versions are affected by CVE-2020-36557?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2020-36557?

Upgrade to a fixed version.

Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.

Is CVE-2020-36557 being exploited?

There is no known exploitation of CVE-2020-36557 in the wild and no public exploit code.

Other vulnerabilities in Linux kernel

• CVE-2026-53266 Linux Kernel Out-of-Bounds Write Exploited High 8.8
• CVE-2013-6282 Linux Kernel Improper Input Validation Exploited High 8.8
• CVE-2022-0185 Linux Kernel Heap-Based Buffer Overflow Exploited High 8.4
• CVE-2013-2094 Linux Kernel Privilege Escalation Exploited High 8.4
• CVE-2026-53362 Linux Kernel Unspecified Exploited High 7.8

All Linux kernel vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as DEBIAN-CVE-2020-36557, GHSA-xjx8-665x-j9wh, UBUNTU-CVE-2020-36557.