CVE-2026-89558Public exploit

Silent data corruption via inverted degradation flag

Published Sep 11, 2026 · Updated Sep 11, 2026

Data corruption in Linux 6.12 allows local users with administrative access to leave recovered RAID10 members with stale data. The raid10_sync_request() recovery loop assigns false to still_degraded when another mirror is missing, causing md_bitmap_start_sync() to clear write-intent bits that the missing member still needs. Triggering the flaw requires an internal-bitmap RAID10 array, missing members in separate mirror pairs, degraded writes, and sequential recovery; the second member is marked in sync despite stale contents.

CVSS severityUnavailable
Unscored
EPSS probability0.63%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Data corruption in Linux 6.12 allows local users with administrative access to leave recovered RAID10 members with stale data. The raid10_sync_request() recovery loop assigns false to still_degraded when another mirror is missing, causing md_bitmap_start_sync() to clear write-intent bits that the missing member still needs. Triggering the flaw requires an internal-bitmap RAID10 array, missing members in separate mirror pairs, degraded writes, and sequential recovery; the second member is marked in sync despite stale contents.

The record

CVE
CVE-2026-89558
Published
Sep 11, 2026
Updated
Sep 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1565.001
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Sep 11, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 11, 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?

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

  1. Affected versionversion=6.12
  2. Affected versionversion=fe6a19d40ceb44281905485f56dda715e3214e0e <00449d752bee9c8787f42ea1bf533a9fb17f9b6b
  3. Affected versionversion=fe6a19d40ceb44281905485f56dda715e3214e0e <0efabe6229dc683dbf6eeebd0f9fddc7971ed420
  4. Affected versionversion=fe6a19d40ceb44281905485f56dda715e3214e0e <47f1441b281decde6954a2fa82b4131637d685ac
  5. Affected versionversion=fe6a19d40ceb44281905485f56dda715e3214e0e <9bb8da6ecb330a5b1ac9b96f1e55f134a7aef1d4

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

The Linux Kernel Organization · Linuxversion=6.12; version=fe6a19d40ceb44281905485f56dda715e3214e0e <00449d752bee9c8787f42ea1bf533a9fb17f9b6b; version=fe6a19d40ceb44281905485f56dda715e3214e0e <0efabe6229dc683dbf6eeebd0f9fddc7971ed420; version=fe6a19d40ceb44281905485f56dda715e3214e0e <47f1441b281decde6954a2fa82b4131637d685ac; version=fe6a19d40ceb44281905485f56dda715e3214e0e <9bb8da6ecb330a5b1ac9b96f1e55f134a7aef1d4

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

Weakness, pattern, technique

T1565.001Stored Data Manipulation

Public exploit references

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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