Race condition in Linux kernel - CVE-2026-74439

 

Race condition in Linux kernel - CVE-2026-74439

Published: August 15, 2026


Vulnerability identifier: #VU142647
CSH Severity: Low
CVSS v4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-74439
CWE-ID: CWE-362
Exploitation vector: Local access
Exploit availability: No public exploit available

Vulnerability details

The vulnerability allows a local user to cause a denial of service.

The vulnerability exists due to improper synchronization in device_pasid_table_teardown() when tearing down scalable-mode context entries. A local user can trigger teardown of a PASID table entry to cause a denial of service.

The issue arises because hardware may fetch a torn entry while the Present bit remains set, which can result in spurious faults or stale walks to freed memory.


Affected software

Linux kernel
Ubuntu
linux (Ubuntu package)
linux-gcp (Ubuntu package)

How to mitigate CVE-2026-74439

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
linux (Ubuntu package) - addressed in versions 7.0.0-34.34, 7.0.0-34.34.1, 7.0.0-34.34~24.04.1, 7.0.0-1012.12~24.04.1, 7.0.0-1013.13, 7.0.0-1013.13~24.04.1, 7.0.0-1014.14, 7.0.0-1020.20
linux-gcp (Ubuntu package) - addressed in versions 7.0.0-1013.13, 7.0.0-1013.13~24.04.1, 7.0.0-1014.14

External References

Related Security Bulletins