CVE-2026-64392

ksmbd: use opener credentials for delete-on-close

CRITICAL
9.1
CVSS Score
Published: July 25, 2026 at 08:50 AM UTC
Updated: October 30, 2026 at 01:19 PM UTC
1 product affected across 1 vendorLinux Kernel

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Severity
CRITICAL9.1
Exploit prediction
EPSS 0.5%

Description

In the Linux kernel, the following vulnerability has been resolved: ksmbd: use opener credentials for delete-on-close Delete-on-close can be completed by deferred or durable handle teardown, where no request work is available. Both the base-file unlink and the ADS xattr removal consequently run with the ksmbd worker credentials and can bypass filesystem permission checks. Run both operations with the credentials captured in struct file when the handle was opened. This preserves the authenticated user's fsuid, fsgid, supplementary groups and capability restrictions at final close.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

5.15 ≤ v < 6.6.1456.13 ≤ v < 6.18.396.19 ≤ v < 7.1.46.7 ≤ v < 6.12.965.15f44158485826c076335d6860d35872271a83791d
Vendor states this is fixed in 18c59109bb6fb816d5102171666f87cf1e29901d (fixed)
Vendor states this is fixed in 4b7059974549d278e30fe70e2a4e421f9839817d (fixed)
Vendor states this is fixed in 52e2f21911158ec961cd5aae19c56460db382af0 (fixed)
Vendor states this is fixed in e72c15085b6d86f45d224d98aa75b5cace4aaab9 (fixed)
Vendor states this is fixed in f08b3f451f12eee4abd8a5981803bc36db84458b (fixed)
Vendor states this is fixed in 5.15 (unaffected)
Vendor states this is fixed in 6.1.191 (unaffected)
Vendor states this is fixed in 6.12.96 (unaffected)
Vendor states this is fixed in 6.18.39 (unaffected)
Vendor states this is fixed in 6.6.145 (unaffected)
Vendor states this is fixed in 7.1.4 (unaffected)
Vendor states this is fixed in 7.2 (unaffected)

CVSS

9.1CRITICALLinux
Vector?

Quick Info

StatusMODIFIED
CWE
NVD-CWE-noinfo

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