CVE-2026-99114 ksmbd: initialize FileSystemControlFlags in FS_CONTROL_INFORMATION
- Exploited in the wild
- Not known
- Fix
- Available
What is CVE-2026-99114?
CVE-2026-99114 is a vulnerability in Linux, published on 28 Oct 2026.
Official description
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: initialize FileSystemControlFlags in FS_CONTROL_INFORMATION
smb2_get_info_filesystem() reports 48 bytes for FS_CONTROL_INFORMATION, that is the whole of struct smb2_fs_control_info, but never assigns FileSystemControlFlags. Those four bytes go to the client as they are found in the response buffer.
The buffer is zeroed on allocation, so a standalone request leaks nothing. A compound request can leak: the offset of the next response is advanced by the length pinned for the previous one, so a reply that was written into the buffer and then dropped in favour of the short error response of smb2_set_err_rsp() stays there, and the next reply is laid over it with only the header cleared.
ksmbd does not implement quota tracking, so report no control flags.
Which versions are affected by CVE-2026-99114?
How do I fix CVE-2026-99114?
Upgrade to a fixed version.
Is CVE-2026-99114 being exploited?
There is no known exploitation of CVE-2026-99114 in the wild and no public exploit code.
Sources
Also known as AZL-111209, BELL-CVE-2026-99114, DEBIAN-CVE-2026-99114, GHSA-hgh8-4rm3-f2vp, UBUNTU-CVE-2026-99114.