Reliance on undefined behavior in Linux kernel - CVE-2026-92505

Vulnerability identifier: #VU151006

CSH Severity: Low

CVSS v4: 0 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:N/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-92505

CWE-ID: CWE-758

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local user to trigger undefined behavior.

The vulnerability exists due to reliance on undefined behavior in the AMD IOMMU devid_write debugfs function when processing a device ID for which no matching PCI segment is found. A local user can write such a device ID to the debugfs interface to trigger undefined behavior.

Linux kernel
Ubuntu
linux (Ubuntu package)
linux-aws (Ubuntu package)
linux-gcp (Ubuntu package)
linux-oracle (Ubuntu package)
linux-ibm (Ubuntu package)
linux-hwe-7.0 (Ubuntu package)
linux-oem-7.0 (Ubuntu package)

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
linux (Ubuntu package) - update to 7.0.0-42.42
linux-aws (Ubuntu package) - update to 7.0.0-1016.17
linux-gcp (Ubuntu package) - update to 7.0.0-1016.18
linux-oracle (Ubuntu package) - update to 7.0.0-1015.16
linux-ibm (Ubuntu package) - update to 7.0.0-1017.17
linux-hwe-7.0 (Ubuntu package) - update to 7.0.0-42.42~24.04.1
linux-oem-7.0 (Ubuntu package) - update to 7.0.0-1017.17

• https://git.kernel.org/stable/c/843e149989665f8309ad2efe6048dc76591e1f94
• https://git.kernel.org/stable/c/8aabe0fba01486b5d893e708b05a8fa7f1b7efbb
• https://git.kernel.org/stable/c/99d42aef089a07cfb1d404a7227ac9dc7628b497

• Reliance on undefined behavior in Linux kernel iommu amd driver
• Ubuntu update for linux-oem-7.0
• Ubuntu update for linux, linux-aws, linux-gcp and more