CVE-2026-64597: Linux kernel · smb: client: fix double-free in SMB2_close() replay
Affects Linux kernelSource CVE Database V5
Not known to be exploited · CVSS 9.8 Critical · fixed in f96e1cdcb63ed3321142ff2fcdf784e32cda8fee : patch Linux kernel as a priority.
Data as of 26 Oct 2026, 17:16 UTC
- EPSS
- 0.3% chance of exploitation in 30 days – higher than 29% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- CISA SSVC
- Exploitation
- No evidence of active exploitation and no public proof of concept
- Automatable
- Attackers can reliably automate steps 1–4 of the kill chain
- Technical impact
- Total control over the software or total information disclosure
CISA SSVC assessment, 2026-10-16.
- Patch
- Available – fixed in f96e1cdcb63ed3321142ff2fcdf784e32cda8fee, d15d83125007f673aec4323e1bbbaaffbe87ea13, b18ed621dbfceecea5539848cddcb9272c9a61e1 +3
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 6 Aug 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 |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in– |
Description
In the Linux kernel, the following vulnerability has been resolved: smb: client: fix double-free in SMB2_close() replay A response-bearing attempt can return a replayable error and free its response buffer. If SMB2_close_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
- git.kernel.org/stable/c/037511726228aaf165c7067ff2bfc88eaecdf1f3 (opens in a new tab)
- git.kernel.org/stable/c/0aa97edf7c347c0f54e7e60c4740574b8120c66a (opens in a new tab)
- git.kernel.org/stable/c/d15d83125007f673aec4323e1bbbaaffbe87ea13 (opens in a new tab)
- git.kernel.org/stable/c/b18ed621dbfceecea5539848cddcb9272c9a61e1 (opens in a new tab)
- git.kernel.org/stable/c/f96e1cdcb63ed3321142ff2fcdf784e32cda8fee (opens in a new tab)