Use-after-free in Linux kernel - CVE-2026-90423

Vulnerability identifier: #VU151061

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-2026-90423

CWE-ID: CWE-416

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local user to trigger a use-after-free condition.

The vulnerability exists due to use-after-free in the rxe_odp_mr_init_user() error-handling path when initializing on-demand paging memory regions. A local user can invoke user memory-region registration during an on-demand paging initialization error to trigger a use-after-free condition.

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 (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/4cfb448705da3171d44d9cbe7be53ff03284d532
• https://git.kernel.org/stable/c/51f2c8d2c99fc1f452f7113c08a35edcc4bf8732
• https://git.kernel.org/stable/c/5f1933163327c9f1c8f2a341c6cb551aaf231ff9

• Use-after-free in Linux kernel sw rxe driver
• Ubuntu update for linux-oem-7.0
• Ubuntu update for linux, linux-aws, linux-gcp and more