What is CVE-2026-64138?

CVE-2026-64138 is a high-severity vulnerability in Linux. CVSS score: 8.8/10. Published 2026-07-19.

How severe is CVE-2026-64138?

High severity. CVSS v3 base score is 8.8 out of 10.

Vulnerability in Linux

CVE-2026-64138

In the Linux kernel, the following vulnerability has been resolved: ksmbd: validate SID in parent security descriptor during ACL inheritance Introduce smb_validate_ntsd_sid() helper to safely validate Owner SID and Group SID inside the NT Security Descriptor (smb_ntsd) retrieved from the parent directory.

EPSS: 0.004 (34.6th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

Affected products

Linux — versions 6.18.34, 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, 7.0.11
Linux Linux_kernel — versions 7.1

References

416baaa9-dc9f-4396-8d5f-8c081fb06d67 (Patch)
416baaa9-dc9f-4396-8d5f-8c081fb06d67 (Patch)
416baaa9-dc9f-4396-8d5f-8c081fb06d67 (Patch)
416baaa9-dc9f-4396-8d5f-8c081fb06d67 (Patch)

Frequently asked questions

What is CVE-2026-64138?: CVE-2026-64138 is a high-severity vulnerability in Linux. CVSS score: 8.8/10. Published 2026-07-19.
How severe is CVE-2026-64138?: High severity. CVSS v3 base score is 8.8 out of 10.