SB2026110852 - Use-after-free in Linux kernel smb server

Description

This security bulletin contains information about 1 vulnerability.

1) Use-after-free (CVE-ID: CVE-2026-99280)

CWE-ID: CWE-416 - Use After Free

CVSSv4: 5.7 [CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

The vulnerability allows a local user to potentially cause a denial of service by triggering access to freed kernel memory.

The vulnerability exists due to a use-after-free in ksmbd session file-table handling when a procfs file-counter read overlaps with file-table destruction during previous-session replacement. A local user can read session file counters during this operation to access the file table's idr during or after its destruction, potentially causing a kernel crash.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/1c087cf7d5386c708d8984b263280b42b3daada0
• https://git.kernel.org/stable/c/6789f0983f8e85ce3a5ed8c50fc05d613ead9c2c