Linux Kernel up to 7.1.8 sched_ext scx_cgroup_lock deadlock

CVSS Meta Temp Score
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CTI Interest Score
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6.2$0-$5k0.00

Summaryinfo

A vulnerability identified as critical has been detected in Linux Kernel up to 7.1.8. This vulnerability affects the function scx_cgroup_lock of the component sched_ext. This manipulation causes deadlock. This vulnerability is registered as CVE-2026-74593. Remote exploitation of the attack is possible. No exploit is available. You should upgrade the affected component.

Detailsinfo

A vulnerability has been found in Linux Kernel up to 7.1.8 and classified as critical. Affected by this vulnerability is the function scx_cgroup_lock of the component sched_ext. The manipulation with an unknown input leads to a deadlock vulnerability. The CWE definition for the vulnerability is CWE-833. The product contains multiple threads or executable segments that are waiting for each other to release a necessary lock, resulting in deadlock. As an impact it is known to affect availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: sched_ext: Take cgroup_lock() first in scx_cgroup_lock() scx_cgroup_lock() write-locks scx_cgroup_ops_rwsem and then takes cgroup_lock(), which can deadlock through kernfs: scx enable/disable cgroup rmdir cpu.weight write ------------------ ------------ ---------------- cgroup_lock() percpu_down_write(rwsem) cgroup_lock() kernfs_get_active() percpu_down_read(rwsem) kernfs_drain() The enable path waits for the rmdir to release cgroup_mutex. The rmdir, deactivating the cpu controller's files, waits in kernfs_drain() for the write's active reference. The write, in scx_group_set_weight(), waits for the rwsem behind the pending writer. Take cgroup_lock() first. The set_* paths take no cgroup locks inside the read side, so a pending write-lock then only waits for read sections that always run to completion, and no dependency from the rwsem back to cgroup_mutex remains.

It is possible to read the advisory at git.kernel.org. This vulnerability is known as CVE-2026-74593 since 08/15/2026. The exploitation appears to be easy. The attack can be launched remotely. Technical details of the vulnerability are known, but there is no available exploit. The attack technique deployed by this issue is T1499 according to MITRE ATT&CK.

The vulnerability scanner Nessus provides a plugin with the ID 338999 (Linux Distros Unpatched Vulnerability : CVE-2026-74593), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 7.1.9 eliminates this vulnerability. Applying the patch a054c9ffa9b7a0dffb763837b91ac9d381ec6d10/5f8b69642d18e1f3e11996707842ac530444e959 is able to eliminate this problem. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the databases at Tenable (338999) and CERT Bund (WID-SEC-2026-2970). Be aware that VulDB is the high quality source for vulnerability data.

Affected

  • Open Source Linux Kernel

Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.5
VulDB Meta Temp Score: 6.2

VulDB Base Score: 6.5
VulDB Temp Score: 6.2
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Deadlock
CWE: CWE-833 / CWE-404
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 338999
Nessus Name: Linux Distros Unpatched Vulnerability : CVE-2026-74593

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 7.1.9
Patch: a054c9ffa9b7a0dffb763837b91ac9d381ec6d10/5f8b69642d18e1f3e11996707842ac530444e959

Timelineinfo

08/15/2026 CVE reserved
08/22/2026 +7 days Advisory disclosed
08/22/2026 +0 days VulDB entry created
08/24/2026 +2 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-74593 (🔒)
GCVE (CVE): GCVE-0-2026-74593
GCVE (VulDB): GCVE-100-394375
CERT Bund: WID-SEC-2026-2970 - Linux Kernel: Mehrere Schwachstellen ermöglichen nicht spezifizierten Angriff

Entryinfo

Created: 08/22/2026 17:56
Updated: 08/24/2026 20:30
Changes: 08/22/2026 17:56 (59), 08/24/2026 02:21 (2), 08/24/2026 20:30 (7)
Complete: 🔍
Cache ID: 216::103

Be aware that VulDB is the high quality source for vulnerability data.

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