CVE-2026-64392Network attack vector

Unauthorized file deletion via worker credentials

Published Jul 25, 2026 · Updated Jul 25, 2026

Improper privilege management in Linux Kernel ksmbd allows remote attackers to delete protected exported data over SMB. Deferred or durable handle teardown runs base-file unlink and ADS xattr removal under ksmbd worker credentials instead of the opener credentials. A valid SMB session and writable share are required, but an anonymous guest session can satisfy the gate when guest writes are enabled.

CVSS severity9.1
Critical
EPSS probability0.47%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper privilege management in Linux Kernel ksmbd allows remote attackers to delete protected exported data over SMB. Deferred or durable handle teardown runs base-file unlink and ADS xattr removal under ksmbd worker credentials instead of the opener credentials. A valid SMB session and writable share are required, but an anonymous guest session can satisfy the gate when guest writes are enabled.

The record

CVE
CVE-2026-64392
Published
Jul 25, 2026
Updated
Jul 25, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
T1485
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 25, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 25, 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=0 <6.12.96
  2. Affected versionversion=0 <6.18.39
  3. Affected versionversion=0 <6.6.145
  4. Affected versionversion=0 <7.1.4
  5. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <18c59109bb6fb816d5102171666f87cf1e29901d
  6. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <4b7059974549d278e30fe70e2a4e421f9839817d
  7. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <52e2f21911158ec961cd5aae19c56460db382af0
  8. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <e72c15085b6d86f45d224d98aa75b5cace4aaab9
  9. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <f08b3f451f12eee4abd8a5981803bc36db84458b

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=0 <6.12.96; version=0 <6.18.39; version=0 <6.6.145; version=0 <7.1.4; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <18c59109bb6fb816d5102171666f87cf1e29901d; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <4b7059974549d278e30fe70e2a4e421f9839817d; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <52e2f21911158ec961cd5aae19c56460db382af0; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <e72c15085b6d86f45d224d98aa75b5cace4aaab9; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <f08b3f451f12eee4abd8a5981803bc36db84458b

Published CVSS scores

9.1Linux kernel CVE teamCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/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)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1485Data Destruction

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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