CVE-2026-64383
A critical vulnerability in the Linux kernel’s SMB client could cause a double‑free error when handling SMB2 flush responses. This flaw could allow an attacker to crash the system or potentially execute arbitrary code. The issue has been fixed in newer kernel releases.
An official fix is available, so this entry is kept for 30 days and then removed automatically.
Who is affected
Linux kernel users, particularly those running SMB client services. The vulnerability affects any system that uses the CIFS/SMB client in the kernel.
Real-world impact
An attacker could crash the system or potentially execute arbitrary code by sending a specially crafted SMB2 flush request that triggers a double‑free.
Why this severity
The CVSS score of 9.8 reflects the vulnerability’s high impact on confidentiality, integrity, and availability, and the fact that it can be exploited remotely without authentication or user interaction.
What to do about it
- 01Upgrade your Linux kernel to a version that includes the fix.
- 02Reboot the system to load the updated kernel.
NVD description indicates the vulnerability has been resolved.
Timeline
- Jul 25, 2026 · 7d agoPublishedDisclosed and added to the National Vulnerability Database.
- Jul 27, 2026 · 5d agoOfficial fix availableA vendor patch or mitigation now exists — see the remediation steps above.