CVE-2026-64379

highCVSS 7.1covered by 2 sourcesfirst seen 2026-07-14

In the Linux kernel, the following vulnerability has been resolved: smb: client: mask server-provided mode to 07777 in modefromsid When modefromsid is active, parse_dacl() applies the server-provided sub_auth[2] value from the NFS mode SID to cf_mode without masking to 07777. Apply the correct masking, same as in the read path.

CSIRTS triage

What: There is a double-free vulnerability in the SMB client related to server-provided mode handling.
Who is affected: Deployments of the Linux kernel with SMB client functionality may be affected.
Urgency: Remediation is important to prevent potential memory corruption, though exploitation is not currently known.
Action: Monitor for updates regarding this issue.

AI-assisted analysis generated from the source advisory — verify against the original.

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Exploitation outlook

Low exploitation risk0.31% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 23% of all EPSS-scored CVEs.

Advisory coverage (2)

highCVE-2026-64379: In the Linux kernel, the following vulnerability has been resolved: smb: client: mask server-p…nvd · 2026-07-25
highCVE-2026-64379: smb: client: mask server-provided mode to 07777 in modefromsidmsrc · 2026-07-14

External references

NVD record for CVE-2026-64379

CVE.org record

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