Use-after-free in Linux kernel - CVE-2026-46154

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Main Vulnerability Database Vulnerabilities #VU133030

Use-after-free in Linux kernel - CVE-2026-46154

Published: May 29, 2026


Vulnerability identifier: #VU133030
CSH Severity: Low
CVSS v4: 5.7 [CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-46154
CWE-ID: CWE-416
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 use-after-free in scx_group_set_{weight,idle,bandwidth}() and sched_ext cgroup setters when racing scheduler disable and enable operations while handling cgroup setting changes. A local user can trigger concurrent cgroup setter activity to dereference a freed scheduler pointer and cause a denial of service.

The issue occurs because a cached scx_root pointer can become stale before scx_cgroup_ops_rwsem is acquired.


Affected software

Linux kernel
Ubuntu
linux (Ubuntu package)
linux-ibm (Ubuntu package)
linux-oem-7.0 (Ubuntu package)
linux-azure (Ubuntu package)
linux-aws (Ubuntu package)

How to mitigate CVE-2026-46154

Install security update from vendor's repository.

linux (Ubuntu package) - addressed in versions 7.0.0-28.28, 7.0.0-28.28.1, 7.0.0-1003.4, 7.0.0-1008.8
linux-ibm (Ubuntu package) - addressed in versions 7.0.0-1008.8, 7.0.0-1010.10
linux-oem-7.0 (Ubuntu package) - update to 7.0.0-1009.9
linux-azure (Ubuntu package) - addressed in versions 7.0.0-1009.9, 7.0.0-1010.10
linux-aws (Ubuntu package) - addressed in versions 7.0.0-1009.9, 7.0.0-1015.15

External References

Related Security Bulletins