CVE-2026-64391
Critical
Description
In the Linux kernel, the following vulnerability has been resolved: ksmbd: use opener credentials for ADS I/O Alternate data streams are stored as xattrs. Unlike regular file I/O, their read and write paths therefore call VFS xattr helpers which recheck inode permissions and LSM policy using the current task credentials. Run ADS I/O with the credentials captured when the SMB handle was opened.
SeverityCritical
CVSS9.8
Exploit probability—
Product
Linux Kernel
PublishedJul 25, 2026
First seenJul 25, 2026
How to fix
Update
- linux linux_kernel6.12.96, 6.18.39, 7.1.4 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| linux linux_kernel | 5.15 ≤ v < 6.12.96, 6.13 ≤ v < 6.18.39, 6.19 ≤ v < 7.1.4 | 6.12.96, 6.18.39, 7.1.4 |
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