CVE-2026-43438

Severity CVSS v4.0:

Pending analysis

Type:

CWE-416 Use After Free

Publication date:

08/05/2026

Last modified:

21/05/2026

Description

In the Linux kernel, the following vulnerability has been resolved: sched_ext: Remove redundant css_put() in scx_cgroup_init() The iterator css_for_each_descendant_pre() walks the cgroup hierarchy under cgroup_lock(). It does not increment the reference counts on yielded css structs. According to the cgroup documentation, css_put() should only be used to release a reference obtained via css_get() or css_tryget_online(). Since the iterator does not use either of these to acquire a reference, calling css_put() in the error path of scx_cgroup_init() causes a refcount underflow. Remove the unbalanced css_put() to prevent a potential Use-After-Free (UAF) vulnerability.

Impact

Vector 3.x

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H CVSS v3.1 Severity and Metrics:

Base Score: 7.80 HIGH
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Attack Vector (AV): Local
Attack Complexity (AC): Low
Privileges Required (PR): Low
User Interaction (UI): None
Scope (S): Unchanged
Confidentiality (C): High
Integrity (I): High
Availability (A): High

Base Score 3.x

7.80

Severity 3.x

HIGH

Vulnerable products and versions

CPE	From	Up to
cpe:2.3:o:linux:linux_kernel::::::::	6.12 (including)	6.12.78 (excluding)
cpe:2.3:o:linux:linux_kernel::::::::	6.13 (including)	6.18.19 (excluding)
cpe:2.3:o:linux:linux_kernel::::::::	6.19 (including)	6.19.9 (excluding)
cpe:2.3:o:linux:linux_kernel:7.0:rc1::::::
cpe:2.3:o:linux:linux_kernel:7.0:rc2::::::

To consult the complete list of CPE names with products and versions, see this page

CVE-2026-43438

Description

Impact

Vulnerable products and versions

References to Advisories, Solutions, and Tools