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VulnerabilityPublished Updated

CVE-2026-64386: Linux kernel · smb: client: fix query_info() replay double-free

Affects Linux kernelSource GCVE Database

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Authoritative record:CVE-2026-64386· Critical 9.8

Not known to be exploited · CVSS 9.8 Critical · fixed in 6.8.0-147.147 : patch Linux kernel as a priority.

Data as of 6 Nov 2026, 17:26 UTC

CVSS 3.1 base score
9.8Critical
How severe the flaw is on the 0–10 CVSS scale.
Patch
Available – fixed in 6.8.0-147.147, 6.8.0-1067.70, 7.0.0-1012.12~24.04.1 +30
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 25 Jul 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponized: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 6 Nov 2026.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

ProductAffectedFixed in
Ubuntu 26.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=resoluteOther threatsAffected
  • <7.0.0-31.31
Fixed in
  • 7.0.0-31.31
Ubuntu 26.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=resoluteOther threatsAffected
  • <7.0.0-1012.12
Fixed in
  • 7.0.0-1012.12
Ubuntu 26.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=resoluteOther threatsAffected
  • <7.0.0-1014.14
Fixed in
  • 7.0.0-1014.14
Ubuntu 26.04 LTSlinux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=resoluteOther threatsAffected
  • <7.0.0-1013.13
Fixed in
  • 7.0.0-1013.13
Ubuntu 26.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=resoluteOther threatsAffected
  • <7.0.0-1011.11
Fixed in
  • 7.0.0-1011.11
Ubuntu 26.04 LTSlinux-gkepkg:deb/ubuntu/linux-gke?arch=source&distro=resoluteOther threatsAffected
  • <7.0.0-1006.7
Fixed in
  • 7.0.0-1006.7

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

A patch is available and has been released in Linux kernel versions 6.8.0-147.147, 6.8.0-1067.70, 7.0.0-1012.12~24.04.1, and other related versions. Users and administrators should update affected Linux kernel packages to these fixed versions or later to remediate the vulnerability. No additional mitigation steps are required beyond applying the official fixes.

Description

A critical double-free vulnerability was identified and fixed in the Linux kernel's SMB client implementation. The flaw occurs in the query_info() function where a replayable error can cause the response buffer to be freed twice, potentially leading to memory corruption. This issue has been resolved by resetting response bookkeeping before each attempt to prevent stale frees. The vulnerability affects multiple Linux kernel versions prior to the fixed releases and has a high CVSS score of 9.8, indicating severe impact on confidentiality, integrity, and availability.

References

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