CVE-2026-90169 ksmbd: free preauth sessions on connection teardown
- Exploited in the wild
- Not known
- Fix
- Available
What is CVE-2026-90169?
CVE-2026-90169 is a vulnerability in Linux, published on 17 Sep 2026.
Official description
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: free preauth sessions on connection teardown
SMB3.1.1 multichannel binding preserves the preauthentication hash in a preauth_session between the NTLM negotiate and authenticate requests. The binding NTLM negotiate allocates this object and returns STATUS_MORE_PROCESSING_REQUIRED. If the client disconnects before it sends the authenticate request, neither the authenticate nor error cleanup paths free the object.
Release any remaining preauthentication sessions when tearing down the connection. Initialize the list when allocating the connection so that this cleanup is safe regardless of the negotiated dialect.
Which versions are affected by CVE-2026-90169?
How do I fix CVE-2026-90169?
Upgrade to a fixed version.
Is CVE-2026-90169 being exploited?
There is no known exploitation of CVE-2026-90169 in the wild and no public exploit code.
Sources
Also known as AZL-102542, BELL-CVE-2026-90169, DEBIAN-CVE-2026-90169, GHSA-p3rj-65j3-jpxc, UBUNTU-CVE-2026-90169.