Use of uninitialized resource in Linux kernel - CVE-2026-46139

 

Use of uninitialized resource in Linux kernel - CVE-2026-46139

Published: May 29, 2026


Vulnerability identifier: #VU133055
CSH Severity: Low
CVSS v4: 4.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-46139
CWE-ID: CWE-908
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 uninitialized memory in build_sec_desc() when building an ACL descriptor. A local user can trigger construction of a security descriptor with a non-zero reserved field to cause a denial of service.

The issue can cause chmod to fail with EINVAL when the malformed security descriptor is rejected.


Affected software

Linux kernel
SUSE Linux Micro Extras
SUSE Linux Micro
Ubuntu
linux (Ubuntu package)
linux-realtime (Ubuntu package)
linux-oracle (Ubuntu package)
linux-gcp (Ubuntu package)
linux-aws (Ubuntu package)
linux-raspi (Ubuntu package)
linux-azure (Ubuntu package)
linux-nvidia (Ubuntu package)
linux-ibm (Ubuntu package)
linux-nvidia-bos (Ubuntu package)
linux-azure-7.0 (Ubuntu package)
linux-oracle-7.0 (Ubuntu package)
linux-gcp-7.0 (Ubuntu package)
linux-oem-7.0 (Ubuntu package)
linux-gke (Ubuntu package)
linux-azure-fde (Ubuntu package)
linux-nvidia-7.0 (Ubuntu package)
kernel-default-devel-debuginfo
kernel-default
kernel-64kb
kernel-64kb-debugsource
kernel-64kb-devel
kernel-default-devel
kernel-syms
kernel-obs-build
kernel-obs-build-debugsource
kernel-default-debugsource
linux-hwe-6.8 (Ubuntu package)
linux-fips (Ubuntu package)
linux-oracle-6.8 (Ubuntu package)
linux-aws-6.8 (Ubuntu package)
linux-azure-fde-6.8 (Ubuntu package)
linux-azure-fips (Ubuntu package)
linux-gcp-fips (Ubuntu package)

How to mitigate CVE-2026-46139

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
linux (Ubuntu package) - addressed in versions 6.8.0-136.136, 6.8.0-1046.50, 6.8.0-1059.67, 6.8.0-1064.72~22.04.1, 6.8.0-1064.72, 6.8.1-1056.57~22.04.2, 6.8.1-1056.57, 7.0.0-28.28
linux-realtime (Ubuntu package) - update to 7.0.0-28.28.1
linux-oracle (Ubuntu package) - update to 7.0.0-1008.8
linux-gcp (Ubuntu package) - update to 7.0.0-1008.8
linux-aws (Ubuntu package) - addressed in versions 6.8.0-1061.64+1, 7.0.0-1009.9
linux-raspi (Ubuntu package) - addressed in versions 6.8.0-1061.65, 6.8.0-2050.52, 7.0.0-1015.15
linux-azure (Ubuntu package) - addressed in versions 6.8.0-1063.71~22.04.1, 6.8.0-1063.71, 7.0.0-1010.10
linux-nvidia (Ubuntu package) - addressed in versions 6.8.0-1059.62~22.04.1, 6.8.0-1059.62, 6.8.0-1059.62.1, 7.0.0-1016.16
linux-ibm (Ubuntu package) - addressed in versions 6.8.0-1030.31, 6.8.0-1033.34, 6.8.0-1061.62~22.04.1, 6.8.0-1061.62, 7.0.0-1010.10
linux-nvidia-bos (Ubuntu package) - update to 7.0.0-2016.16
linux-azure-7.0 (Ubuntu package) - update to 7.0.0-1014.14~24.04.1
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-oem-7.0 (Ubuntu package) - update to 7.0.0-1009.9
linux-gke (Ubuntu package) - update to 7.0.0-1003.4
linux-azure-fde (Ubuntu package) - addressed in versions 6.8.0-1062.69, 7.0.0-1009.9
linux-nvidia-7.0 (Ubuntu package) - update to 7.0.0-1016.16~24.04.1
kernel-default-devel-debuginfo - update to 6.4.0-159998.55.1
kernel-default - update to 6.4.0-159998.55.1
kernel-64kb - update to 6.4.0-159998.55.1
kernel-64kb-debugsource - update to 6.4.0-159998.55.1
kernel-64kb-devel - update to 6.4.0-159998.55.1
kernel-default-devel - update to 6.4.0-159998.55.1
kernel-syms - update to 6.4.0-159998.55.1
kernel-obs-build - update to 6.4.0-159998.55.1
kernel-obs-build-debugsource - update to 6.4.0-159998.55.1
kernel-default-debugsource - update to 6.4.0-159998.55.1
linux-hwe-6.8 (Ubuntu package) - update to 6.8.0-136.136~22.04.1
linux-fips (Ubuntu package) - addressed in versions 6.8.0-136.136+fips2, 6.8.0-136.136.2~22.04.1, 6.8.0-136.136.2, 6.8.0-1058.61
linux-oracle-6.8 (Ubuntu package) - update to 6.8.0-1058.61~22.04.1
linux-aws-6.8 (Ubuntu package) - addressed in versions 6.8.0-1061.64~22.04.1, 6.8.0-1061.64+fips1
linux-azure-fde-6.8 (Ubuntu package) - update to 6.8.0-1062.69~22.04.1
linux-azure-fips (Ubuntu package) - update to 6.8.0-1063.71+fips2
linux-gcp-fips (Ubuntu package) - update to 6.8.0-1064.72+fips1

External References

Related Security Bulletins