CVE-2026-93812 ksmbd: fix sd_ndr.data memory leak in ksmbd_vfs_set_sd_xattr
A memory leak in the Linux kernel's ksmbd module allows attackers to cause a denial of service by triggering encoding errors.
- 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-2026-93812?
CVE-2026-93812 is a denial of service vulnerability in Linux, published on 24 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:
ksmbd: fix sd_ndr.data memory leak in ksmbd_vfs_set_sd_xattr
ndr_encode_v4_ntacl() allocates sd_ndr.data via kzalloc() at entry. If any subsequent ndr_write_*() call returns error during encoding, the allocated sd_ndr.data won't be freed and causes memory leak.
Move kfree(sd_ndr.data) into out label to ensure the buffer gets released on all success and error return paths.
Which versions are affected by CVE-2026-93812?
How do I fix CVE-2026-93812?
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-2026-93812 being exploited?
There is no known exploitation of CVE-2026-93812 in the wild and no public exploit code.
Sources
Also known as AZL-103949, BELL-CVE-2026-93812, DEBIAN-CVE-2026-93812, GHSA-7f3p-w572-qm2q, UBUNTU-CVE-2026-93812.