NULL pointer dereference in Linux kernel - CVE-2026-64183

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Main Vulnerability Database Vulnerabilities #VU138435

NULL pointer dereference in Linux kernel - CVE-2026-64183

Published: July 20, 2026


Vulnerability identifier: #VU138435
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-2026-64183
CWE-ID: CWE-476
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 a NULL pointer dereference in the EFI runtime workqueue handling for ACPI PRM calls when invoking EFI runtime calls during early initialization. A local user can trigger early PRM-related runtime calls to cause a denial of service.

The issue occurs when ACPI PRM accesses happen before the EFI runtime workqueue has been allocated during system initialization.


Affected software

Linux kernel
Ubuntu
linux (Ubuntu package)
linux-lowlatency (Ubuntu package)
linux-nvidia-tegra (Ubuntu package)
linux-gcp-6.8 (Ubuntu package)
linux-oracle (Ubuntu package)
linux-aws-fips (Ubuntu package)
linux-aws (Ubuntu package)
linux-azure (Ubuntu package)
linux-azure-fips (Ubuntu package)
linux-azure-6.8 (Ubuntu package)
linux-raspi-realtime (Ubuntu package)
linux-ibm (Ubuntu package)
linux-oracle-7.0 (Ubuntu package)
linux-gcp-7.0 (Ubuntu package)
linux-azure-7.0 (Ubuntu package)
linux-nvidia (Ubuntu package)
linux-nvidia-bos (Ubuntu package)

How to mitigate CVE-2026-64183

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
linux (Ubuntu package) - addressed in versions 6.8.0-139.139+fips1, 6.8.0-1049.53, 6.8.0-1062.65+fips1, 6.8.0-1062.65.1, 6.8.0-1062.65~22.04.1, 6.8.0-1062.70, 6.8.0-1064.68, 6.8.0-1067.75, 6.8.0-1067.75+fips1, 6.8.1-1059.60, 6.8.1-1059.60~22.04.1
linux-lowlatency (Ubuntu package) - addressed in versions 6.8.0-139.139.1, 6.8.0-139.139.1~22.04.1
linux-nvidia-tegra (Ubuntu package) - update to 6.8.0-1035.38
linux-gcp-6.8 (Ubuntu package) - addressed in versions 6.8.0-1036.37, 6.8.0-1064.65, 6.8.0-1067.75~22.04.1
linux-oracle (Ubuntu package) - addressed in versions 6.8.0-1061.64, 6.8.0-1061.64~22.04.1
linux-aws-fips (Ubuntu package) - update to 6.8.0-1064.67+fips1
linux-aws (Ubuntu package) - addressed in versions 6.8.0-1064.67~22.04.1, 7.0.0-1009.9, 7.0.0-1015.15
linux-azure (Ubuntu package) - addressed in versions 6.8.0-1067.75, 7.0.0-1009.9, 7.0.0-1010.10
linux-azure-fips (Ubuntu package) - update to 6.8.0-1067.75+fips1
linux-azure-6.8 (Ubuntu package) - update to 6.8.0-1067.75~22.04.1
linux-raspi-realtime (Ubuntu package) - update to 6.8.0-2053.55
linux-ibm (Ubuntu package) - addressed in versions 7.0.0-1008.8, 7.0.0-1010.10
linux-oracle-7.0 (Ubuntu package) - update to 7.0.0-1011.11~24.04.1
linux-gcp-7.0 (Ubuntu package) - update to 7.0.0-1011.11~24.04.1
linux-azure-7.0 (Ubuntu package) - update to 7.0.0-1014.14~24.04.1
linux-nvidia (Ubuntu package) - addressed in versions 7.0.0-1016.16, 7.0.0-1016.16~24.04.1
linux-nvidia-bos (Ubuntu package) - update to 7.0.0-2016.16

External References

Related Security Bulletins