CVE-2026-64385: Linux kernel · smb: client: fix double-free in SMB2_ioctl() replay
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 9.8 Critical · fixed in 7.0.0-1012.12~24.04.1 : patch Linux kernel as a priority.
Data as of 26 Oct 2026, 13:47 UTC
- EPSS
- 0.4% chance of exploitation in 30 days – higher than 39% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 7.0.0-1012.12~24.04.1, 7.0.0-1011.11~24.04.1, 7.0.0-31.31~24.04.1 +7
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 25 Jul 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by 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 26 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-gkepkg:deb/ubuntu/linux-gke?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
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 from Ubuntu as part of the Linux kernel updates for the affected versions. Users should apply the updates to the linux-hwe-edge kernel packages and reboot their systems to complete remediation. Due to an ABI change, recompilation and reinstallation of any third-party kernel modules is necessary after updating. Follow the vendor advisory instructions for updating to the fixed package versions.
Description
In the Linux kernel, the following vulnerability has been resolved: smb: client: fix double-free in SMB2_ioctl() replay A response-bearing attempt can return a replayable error and free its response buffer. If SMB2_ioctl_init() fails before the next send, cleanup retains the previous buffer type and frees that response again. Reset response bookkeeping before each attempt to prevent the stale free.
References
- nvd.nist.gov/vuln/detail/CVE-2026-64385 (opens in a new tab)
- git.kernel.org/stable/c/0be4bc64882edaefaaee8d1e27d083643eb778e6 (opens in a new tab)
- git.kernel.org/stable/c/276c8efbc49f9303ac76d0d4deab7128581b0f3b (opens in a new tab)
- git.kernel.org/stable/c/96fcfc8ae7359346156e492ca610e830d2649ad6 (opens in a new tab)
- git.kernel.org/stable/c/f9bbadb6c94583e3b4af1afc449bfceb1d1ddec9 (opens in a new tab)
- git.kernel.org/stable/c/fc65ffb4ef1bf540da16b17c225ae51091e07d72 (opens in a new tab)
- ubuntu.com/security/CVE-2026-64385 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-64385 (opens in a new tab)
- git.kernel.org/linus/f9bbadb6c94583e3b4af1afc449bfceb1d1ddec9 (opens in a new tab)
- ubuntu.com/security/notices/USN-8726-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8727-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8728-1 (opens in a new tab)