CVE-2023-53859

Kernel warning via instrumented s390 idle entry

Published Dec 9, 2025 · Updated May 23, 2026

Improper instrumentation in the Linux kernel causes a trace-recursion warning when an affected s390 processor enters CPU idle. The arch_cpu_idle() entry lacks the noinstr annotation, so ftrace instruments code reached while RCU is not watching and emits the warning. The condition requires the s390 architecture and CONFIG_ARCH_WANTS_NO_INSTR; the published record identifies no attacker-controlled vector or consequence beyond the warning.

CVSS severityUnavailable
Unscored
EPSS probability0.22%
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

Improper instrumentation in the Linux kernel causes a trace-recursion warning when an affected s390 processor enters CPU idle. The arch_cpu_idle() entry lacks the noinstr annotation, so ftrace instruments code reached while RCU is not watching and emits the warning. The condition requires the s390 architecture and CONFIG_ARCH_WANTS_NO_INSTR; the published record identifies no attacker-controlled vector or consequence beyond the warning.

The record

CVE
CVE-2023-53859
Published
Dec 9, 2025
Updated
May 23, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
Unavailable
Attack vector
Unavailable
Privileges
Unavailable

Timeline

How it unfolded

  1. Dec 9, 2025CVE publishedPublication date reported by the CVE source.
  2. May 23, 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=1098582a0f6c4e8fd28da0a6305f9233d02c9c1d <49aa49952116b8fd56bfb1e8c69bce179f49bece
  2. Affected versionversion=1098582a0f6c4e8fd28da0a6305f9233d02c9c1d <611c390217106c46e24e1af3db83187339d447ea
  3. Affected versionversion=1098582a0f6c4e8fd28da0a6305f9233d02c9c1d <a9cbc1b471d291c865907542394f1c483b93a811
  4. Affected versionversion=1098582a0f6c4e8fd28da0a6305f9233d02c9c1d <fc60c4f12d8a056f20d8f4d0086a36c68ffa9fdc
  5. Affected versionversion=4.19.297 <4.20
  6. Affected versionversion=5.9
  7. Affected versionversion=788621afda4101ca0fae48de424040cda78193fe

What conditions does exploitation require?

Attack vectorUnavailable in this record.
Required privilegesUnavailable in this record.

What is affected?

The Linux Kernel Organization · Linuxversion=1098582a0f6c4e8fd28da0a6305f9233d02c9c1d <49aa49952116b8fd56bfb1e8c69bce179f49bece; version=1098582a0f6c4e8fd28da0a6305f9233d02c9c1d <611c390217106c46e24e1af3db83187339d447ea; version=1098582a0f6c4e8fd28da0a6305f9233d02c9c1d <a9cbc1b471d291c865907542394f1c483b93a811; version=1098582a0f6c4e8fd28da0a6305f9233d02c9c1d <fc60c4f12d8a056f20d8f4d0086a36c68ffa9fdc; version=4.19.297 <4.20; version=5.9; version=788621afda4101ca0fae48de424040cda78193fe

Published CVSS scores

No CVSS assessment is available in this record.

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)
VectorUnavailable
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

No sourced classifications are available.

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