CVE-2023-53522

Local service hang via cgroup freezer deadlock

Published Oct 1, 2025 · Updated May 11, 2026

Deadlock in Linux kernel 6.1 before 6.1.25 and 6.2 before 6.2.12 allows local users to hang cgroup freezer operations via writes. freezer_change_state() takes freezer_mutex before freezer_apply_state() enters static_branch_inc(), which takes cpu_hotplug_lock in the reverse order used by cgroup task migration. Reachability requires local low-privileged access to writable legacy cgroup freezer controls, and successful triggering can block affected cgroup operations.

CVSS severity7.8
High
EPSS probability0.15%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Deadlock in Linux kernel 6.1 before 6.1.25 and 6.2 before 6.2.12 allows local users to hang cgroup freezer operations via writes. freezer_change_state() takes freezer_mutex before freezer_apply_state() enters static_branch_inc(), which takes cpu_hotplug_lock in the reverse order used by cgroup task migration. Reachability requires local low-privileged access to writable legacy cgroup freezer controls, and successful triggering can block affected cgroup operations.

The record

CVE
CVE-2023-53522
Published
Oct 1, 2025
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Oct 1, 2025CVE publishedPublication date reported by the CVE source.
  2. May 11, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=6.1
  2. Affected versionversion=f5d39b020809146cc28e6e73369bf8065e0310aa <34fbb7b45bae20b551dda24337c7761ca13ce69d
  3. Affected versionversion=f5d39b020809146cc28e6e73369bf8065e0310aa <3756171b97c307d9df8b8ded1d883eec30172085
  4. Affected versionversion=f5d39b020809146cc28e6e73369bf8065e0310aa <57dcd64c7e036299ef526b400a8d12b8a2352f26

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=6.1; version=f5d39b020809146cc28e6e73369bf8065e0310aa <34fbb7b45bae20b551dda24337c7761ca13ce69d; version=f5d39b020809146cc28e6e73369bf8065e0310aa <3756171b97c307d9df8b8ded1d883eec30172085; version=f5d39b020809146cc28e6e73369bf8065e0310aa <57dcd64c7e036299ef526b400a8d12b8a2352f26

Published CVSS scores

7.8Canonical UbuntuCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo