CVE-2026-80727

Kernel debug warnings via premature timer modification

Published Sep 3, 2026 · Updated Sep 3, 2026

Initialization-order error in the Linux x86 MCE subsystem causes kernel debug warnings during CMCI discovery early in system startup. In arch/x86/kernel/cpu/mce/core.c, CMCI storm discovery calls mce_timer_kick to modify the polling timer before __mcheck_cpu_setup_timer initializes it. The disclosed condition requires x86 CMCI storm discovery during boot; the upstream record demonstrates debug-object warnings but reports no attacker-controlled trigger or service interruption.

CVSS severityUnavailable
Unscored
EPSS probability0.20%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Initialization-order error in the Linux x86 MCE subsystem causes kernel debug warnings during CMCI discovery early in system startup. In arch/x86/kernel/cpu/mce/core.c, CMCI storm discovery calls mce_timer_kick to modify the polling timer before __mcheck_cpu_setup_timer initializes it. The disclosed condition requires x86 CMCI storm discovery during boot; the upstream record demonstrates debug-object warnings but reports no attacker-controlled trigger or service interruption.

The record

CVE
CVE-2026-80727
Published
Sep 3, 2026
Updated
Sep 3, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
Unavailable
Attack vector
Unavailable
Privileges
Unavailable

Timeline

How it unfolded

  1. Sep 3, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 3, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

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  1. Affected versionversion=1f68ce2a027250aeeb1756391110cdc4dc97c797 <17ab68d0cf6a41bff61b1e13c6141d9e463736ae
  2. Affected versionversion=1f68ce2a027250aeeb1756391110cdc4dc97c797 <4f4cba3947d2f0eceb32727e198ca2c149a653a9
  3. Affected versionversion=1f68ce2a027250aeeb1756391110cdc4dc97c797 <a213dfaa2596c1c0dc4dae91c14fbfa499c03223
  4. Affected versionversion=1f68ce2a027250aeeb1756391110cdc4dc97c797 <e708fc1566ebd4a2d3f2546e6310d64d362db80d
  5. Affected versionversion=6.8

What conditions does exploitation require?

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

What is affected?

The Linux Kernel Organization · Linuxversion=1f68ce2a027250aeeb1756391110cdc4dc97c797 <17ab68d0cf6a41bff61b1e13c6141d9e463736ae; version=1f68ce2a027250aeeb1756391110cdc4dc97c797 <4f4cba3947d2f0eceb32727e198ca2c149a653a9; version=1f68ce2a027250aeeb1756391110cdc4dc97c797 <a213dfaa2596c1c0dc4dae91c14fbfa499c03223; version=1f68ce2a027250aeeb1756391110cdc4dc97c797 <e708fc1566ebd4a2d3f2546e6310d64d362db80d; version=6.8

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.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 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

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Your stack

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