CVE-2026-98450 smb: client: close completed creates on compound wait errors
A flaw in the Linux kernel SMB client fails to close remote handles on compound wait errors, potentially leading to resource exhaustion and denial of service.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-98450?
CVE-2026-98450 is a denial of service vulnerability in Linux, published on 18 Oct 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
smb: client: close completed creates on compound wait errors
compound_send_recv() waits for responses in order. If a later wait is interrupted, or if a later MID fails during response synchronization, an earlier CREATE may already have opened a remote handle. The earlier mid is then released without invoking handle_cancelled_mid(), leaving the remote handle open because no FID was copied to the caller.
Mark completed earlier mids as cancelled when a compound wait or MID synchronization aborts. Keep their response buffers attached while the MIDs are synchronized, and transfer them only after synchronization of the processed responses, so the release path can inspect successful CREATE responses and queue SMB2_close() after a later failure. Account for a remote open only after the close work is allocated and before it is queued, since the caller has not yet updated num_remote_opens. Mark the create+close compound used by smb2_unlink() so it is not closed again. Non-CREATE responses and compounds that already include a close keep their existing behavior.
Which versions are affected by CVE-2026-98450?
How do I fix CVE-2026-98450?
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-2026-98450 being exploited?
There is no known exploitation of CVE-2026-98450 in the wild and no public exploit code.
Sources
Also known as AZL-108717, BELL-CVE-2026-98450, DEBIAN-CVE-2026-98450, GHSA-vqm5-qg35-949v, UBUNTU-CVE-2026-98450.