CVE-2023-53273 Drivers: vmbus: Check for channel allocation before looking up relids

What is CVE-2023-53273?

CVE-2023-53273 is a medium-severity vulnerability in Linux kernel, published on 16 Sep 2025. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

In the Linux kernel, the following vulnerability has been resolved:

Drivers: vmbus: Check for channel allocation before looking up relids

relid2channel() assumes vmbus channel array to be allocated when called. However, in cases such as kdump/kexec, not all relids will be reset by the host. When the second kernel boots and if the guest receives a vmbus interrupt during vmbus driver initialization before vmbus_connect() is called, before it finishes, or if it fails, the vmbus interrupt service routine is called which in turn calls relid2channel() and can cause a null pointer dereference.

Print a warning and error out in relid2channel() for a channel id that's invalid in the second kernel.

Weakness: CWE-476

Which versions are affected by CVE-2023-53273?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2023-53273?

Apply the vendor's patch.

Is CVE-2023-53273 being exploited?

There is no known exploitation of CVE-2023-53273 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 BELL-CVE-2023-53273, DEBIAN-CVE-2023-53273, GHSA-h7h5-4hm9-wwx3, UBUNTU-CVE-2023-53273.