CVE-2020-27786 Use after free in kernel

What is CVE-2020-27786?

CVE-2020-27786 is a high-severity use after free vulnerability in Linux kernel, published on 11 Dec 2020. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

A flaw was found in the Linux kernel’s implementation of MIDI, where an attacker with a local account and the permissions to issue ioctl commands to midi devices could trigger a use-after-free issue. A write to this specific memory while freed and before use causes the flow of execution to change and possibly allow for memory corruption or privilege escalation. The highest threat from this vulnerability is to confidentiality, integrity, as well as system availability.

Weakness: CWE-416

Which versions are affected by CVE-2020-27786?

It affects 6 products.

Products include Linux kernel, Netapp Cloud Backup, Netapp Solidfire Baseboard Management Controller, Redhat Enterprise Linux, Redhat Enterprise Mrg, Redhat Openshift Container Platform.

How do I fix CVE-2020-27786?

Apply the vendor's patch.

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-2020-27786 being exploited?

There is no known exploitation of CVE-2020-27786 in the wild and no public exploit code.

Public exploit code: 4 proofs of concept on GitHub.

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 A-175769013, DEBIAN-CVE-2020-27786, GHSA-3mfq-6299-p3w3, PUB-A-175769013, UBUNTU-CVE-2020-27786.