CVE-2026-90152 smb/server: fix session leak in ksmbd_session_register()
A session leak in the Linux kernel's ksmbd SMB server allows authenticated users to exhaust resources, causing denial of service.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-90152?
CVE-2026-90152 is a denial of service vulnerability in Linux, published on 17 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
smb/server: fix session leak in ksmbd_session_register()
See the procedure below:
smb2_sess_setup ksmbd_smb2_session_create __session_create atomic_set(&sess->refcnt, 2) hash_add(sessions_table, &sess->hlist, sess->id) ksmbd_session_register xa_store(&conn->sessions, sess->id, sess) // fail ksmbd_user_session_put atomic_dec(&sess->refcnt) // refcnt is 1, session is not freed
Remove the session from sessions_table and drop its table reference if xa_store() fails.
Which versions are affected by CVE-2026-90152?
How do I fix CVE-2026-90152?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-90152 being exploited?
There is no known exploitation of CVE-2026-90152 in the wild and no public exploit code.
Sources
Also known as AZL-102975, BELL-CVE-2026-90152, DEBIAN-CVE-2026-90152, GHSA-c2gf-579m-pqr2, UBUNTU-CVE-2026-90152.