SB20260815343 - Use-after-free in Linux kernel smb server
Published: August 15, 2026
Security Bulletin ID
SB20260815343
CSH Severity
Medium
Patch available
YES
Number of vulnerabilities
1
Exploitation vector
Remote access
Highest impact
Denial of service
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 vulnerability.
1) Use-after-free (CVE-ID: CVE-2026-72381)
CWE-ID: CWE-416 - Use After Free
CVSSv4: 7.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a remote user to cause a denial of service.
The vulnerability exists due to a use-after-free in ksmbd_vfs_compare_durable_owner() when processing concurrent SMB2 durable reconnect requests on the same persistent_id. A remote user can trigger concurrent durable reconnect operations to cause a denial of service.
The issue occurs because a comparison of owner.name can race with memory being freed in the durable file reopen path.
Remediation
Install update from vendor's website.
References
- https://git.kernel.org/stable/c/38637163501fd9e2f684b8cd275d0db5d79f37c6
- https://git.kernel.org/stable/c/5a5ac2852cd326529d02f778bc1aa6184701f4d7
- https://git.kernel.org/stable/c/93d4d46bf9d442a12ea87278049ec416962c627f
- https://git.kernel.org/stable/c/ed98719be41389d416953b8ef9f07a07dfea6b2b
- https://git.kernel.org/stable/c/fb978d72052704c6b06c6b0f129fcd60b77169f5