CVE-2026-68457: ksmbd: use opener credentials for FSCTL mutations
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: use opener credentials for FSCTL mutations
SETSPARSE, SETZERODATA and SETCOMPRESSION operate on an open SMB handle but call VFS xattr, fallocate or fileattr helpers with the current ksmbd worker credentials. Those helpers can revalidate inode permissions, ownership and LSM policy independently of the SMB handle access mask.
Run each operation with the credentials captured in the target file when the handle was opened. Keep credential handling local to these single-file FSCTLs rather than applying session credentials to the complete IOCTL handler, which also contains handle-less and multi-handle operations.
Affected Software
Event History
Frequently Asked Questions
What is the severity of CVE-2026-68457?
CVE-2026-68457 has a risk score of 37, indicating a potentially high impact on the system.
How do I fix CVE-2026-68457?
To mitigate CVE-2026-68457, ensure you update the Linux Kernel to the latest patched version that addresses this vulnerability.
What systems are affected by CVE-2026-68457?
CVE-2026-68457 affects Linux Kernel implementations that utilize the ksmbd SMB server functionality.
What kind of attacks can exploit CVE-2026-68457?
CVE-2026-68457 can potentially allow attackers to manipulate file operations on SMB shares, using incorrect user credentials.
Is CVE-2026-68457 a remote vulnerability?
Yes, CVE-2026-68457 can be exploited remotely if an attacker has access to the SMB share.