Kernel-level SMB client bug in upstream Linux affects many distributions and can crash or enable remote code execution; widespread OS impact merits broad alert.
CVE-2026-64384
Linux kernel SMB client double-free: remote memory corruption and RCE risk.
Is CVE-2026-64384 being exploited?
Not confirmed. CVE-2026-64384 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.46% probability of exploitation in the next 30 days.
How severe is CVE-2026-64384?
CVE-2026-64384 is rated Critical with a CVSS score of 9.8. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-64384?
Yes. A fix has been recorded for CVE-2026-64384. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-64384 affect?
CVE-2026-64384 affects Linux kernel SMB/CIFS client (SMB2/SMB3), Linux distributions using affected kernels. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-64384?
Apply vendor kernel updates and reboot affected systems immediately.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Remote memory corruption via replayed SMB response (double-free) allowing kernel crashes or possible remote code execution on affected hosts.
Immediate action required
- affected>= 433042a91f9373241307725b52de573933ffedbf and < 5821f9dbb8b5b24391850a13418e633edd0fb003
- affected>= 4f1fffa2376922f3d1d506e49c0fd445b023a28e and < d684f4134998085702009b94c35c2003fc9e72d3
- affected>= 4f1fffa2376922f3d1d506e49c0fd445b023a28e and < 52af1975f0dfae990c5a0e85872cc41be0e88a68
- affected>= 4f1fffa2376922f3d1d506e49c0fd445b023a28e and < 901891513951bc8322ece754863909ea45af95c6
- affected>= 4f1fffa2376922f3d1d506e49c0fd445b023a28e and < 145f820dcbb2cced374f2532f8a61a44dce4a615
- affected>= 6.6.32 and < 6.6.145
- affected6.8
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.