CVE & CISA-KEV Catalog

CVE-2026-43438

HIGH
7.8
CVSS v3
NVD

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.

How to fix

Remediation Available
linuxDebian
Fixed in:6.12.85-1CVE-2026-43438
Fixed in:6.19.10-1CVE-2026-43438

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorLocal
Attack ComplexityLow
Privileges RequiredLow
User InteractionNone
ScopeUnchanged

Impact

ConfidentialityHigh
IntegrityHigh
AvailabilityHigh

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Exploit Intelligence

0.13%probability of exploitation in 30 days
3rdpercentile

Low risk: more likely to be exploited than 3% of all known CVEs.

References

Related Vulnerabilities

Other CWE-416 (Use After Free) vulnerabilities, ordered by exploit likelihood. View all

CVESeverityCVSSEPSSExploitedFix
CVE-2019-0708Critical9.8100%KEV + Ransom-
CVE-2021-31166Critical9.8100%KEVFix
CVE-2015-5119Critical9.899%KEV-
CVE-2010-3962High8.197%KEV-
CVE-2015-0313Critical9.896%KEVFix
CVE-2017-9798High7.595%-Fix
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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-05-21.