What’s Vulnerable › Vulnerabilities

CVE-2026-64379: smb: client: mask server-provided mode to 07777 in modefromsid

• Severity: high (CVSS 7.1 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-07-25 · updated 2026-10-19
• Weakness: CWE-20

Description

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.

Affected products

• Linux kernel: from 5.4 before 5.10.261; from 5.11 before 5.15.212; from 5.16 before 6.1.178; from 6.2 before 6.6.145; from 6.7 before 6.12.96; from 6.13 before 6.18.39 — fixed in 5.10.261, 5.15.212, 6.1.178, 6.12.96, 6.18.39, 6.6.145

How to fix

Upgrade to a fixed version: Linux kernel 5.10.261, 5.15.212, 6.1.178, 6.12.96. Check the vendor advisory for mitigations.

References

• https://git.kernel.org/stable/c/08c600b7e1818539ba5efee4cdb06215c245ca78
• https://git.kernel.org/stable/c/5f6f2241034f189c69d4d0b5f8fe24a0c25b0c14
• https://git.kernel.org/stable/c/b84e002e0df26bbc6cbd3ca01b8212601fe0ae7d
• https://git.kernel.org/stable/c/c6c484a7d5bff6b929a86d7ed5130f29834c6a0d
• https://git.kernel.org/stable/c/e3d9c7160d483fc8f9e225aafad8ecbbc43f3151
• https://git.kernel.org/stable/c/ee2216dbdf0c677e89bb43e03247dba590ed00ef
• https://git.kernel.org/stable/c/f511807feee7cb29b61bdfa86472c7e9e2e5df94
• https://git.kernel.org/stable/c/f80add1bfb3425100a325b14f19648e75669a954

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