CVE-2023-2236 Use-after-free in Linux kernel's Performance Events subsystem

What is CVE-2023-2236?

CVE-2023-2236 is a high-severity use after free vulnerability in Linux kernel, published on 1 May 2023. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

A use-after-free vulnerability in the Linux Kernel io_uring subsystem can be exploited to achieve local privilege escalation.

Both io_install_fixed_file and its callers call fput in a file in case of an error, causing a reference underflow which leads to a use-after-free vulnerability.

We recommend upgrading past commit 9d94c04c0db024922e886c9fd429659f22f48ea4.

Weakness: CWE-416

Which versions are affected by CVE-2023-2236?

It affects 2 products.

Products include Linux kernel, Netapp Hci Baseboard Management Controller.

How do I fix CVE-2023-2236?

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-2023-2236 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2023-2236 exists.

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-2023-2236, GHSA-j4r5-9qqm-p694, UBUNTU-CVE-2023-2236.