Kernel-level double-free in widely deployed Linux SMB client can cause remote kernel memory corruption, DoS or RCE across many systems; high-impact for enterprise infrastructure.
CVE-2026-64385
Double-free in Linux SMB client (SMB2_ioctl) allowing kernel memory corruption.
Is CVE-2026-64385 being exploited?
Not confirmed. CVE-2026-64385 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-2026-64385?
CVE-2026-64385 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-2026-64385?
Yes. A fix has been recorded for CVE-2026-64385. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-64385 affect?
CVE-2026-64385 affects Linux kernel SMB client (CIFS/SMB2_ioctl), Linux distributions using vulnerable kernel builds. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-64385?
Apply vendor kernel security updates ASAP; block untrusted SMB servers.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Malformed SMB server responses can trigger kernel double-free, causing crash (DoS) or potentially remote code execution and privilege escalation.
Immediate action required
- affected>= 433042a91f9373241307725b52de573933ffedbf and < 0be4bc64882edaefaaee8d1e27d083643eb778e6
- affected>= 4f1fffa2376922f3d1d506e49c0fd445b023a28e and < 96fcfc8ae7359346156e492ca610e830d2649ad6
- affected>= 4f1fffa2376922f3d1d506e49c0fd445b023a28e and < 276c8efbc49f9303ac76d0d4deab7128581b0f3b
- affected>= 4f1fffa2376922f3d1d506e49c0fd445b023a28e and < fc65ffb4ef1bf540da16b17c225ae51091e07d72
- affected>= 4f1fffa2376922f3d1d506e49c0fd445b023a28e and < f9bbadb6c94583e3b4af1afc449bfceb1d1ddec9
- 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.