Division by zero in Linux kernel - CVE-2026-72238
Published: August 16, 2026
Vulnerability details
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to division by zero in early_serial_init() when parsing the console=uart8250 boot parameter. A local user can supply an empty, zero, invalid, or overflowing baud rate value to cause a denial of service.
The issue causes the system to hang during early boot.
Affected software
Ubuntu
linux-nvidia (Ubuntu package)
linux-gcp-7.0 (Ubuntu package)
linux (Ubuntu package)
linux-oem-7.0 (Ubuntu package)
linux-azure-7.0 (Ubuntu package)
linux-azure (Ubuntu package)
How to mitigate CVE-2026-72238
linux-nvidia (Ubuntu package) - addressed in versions 5.15.0-1112.113, 5.15.0.1112.112
linux-gcp-7.0 (Ubuntu package) - addressed in versions 7.0.0-38.38~24.04.4, 7.0.0-1013.13~24.04.1, 7.0.0-1014.14~24.04.1
linux (Ubuntu package) - addressed in versions 7.0.0-38.38, 7.0.0-38.38.1, 7.0.0-1008.9, 7.0.0-1013.13~24.04.1, 7.0.0-1014.14, 7.0.0-1015.15
linux-oem-7.0 (Ubuntu package) - update to 7.0.0-1015.15
linux-azure-7.0 (Ubuntu package) - addressed in versions 7.0.0-1016.16~24.04.1, 7.0.0-1017.17~24.04.1
linux-azure (Ubuntu package) - addressed in versions 7.0.0-1016.16, 7.0.0-1017.17
External References
- https://git.kernel.org/stable/c/24fbed0a2a45f5f379ef2b53bd2abe58be1142ad
- https://git.kernel.org/stable/c/4dad7e870c7e5178f71b5e1e4f67934b9e8cc207
- https://git.kernel.org/stable/c/9a77a7639dfdc3eca417cd37620ce64da79c80c4
- https://git.kernel.org/stable/c/b4d05032e9af7137eab8f3af2855073f896ca843
- https://git.kernel.org/stable/c/c1a276a731d02cbb728d0530f327a68728f2d8b0
- https://git.kernel.org/stable/c/efa96a22613b86e05cd81229ce0be411c1a4a79a
- https://git.kernel.org/stable/c/f7c67c97b37c11f2a95c204092fb8159f2779e8f
- https://git.kernel.org/stable/c/ffa0aa5b625fe0bed7463ac613f8b06676ff4542