CVE-2026-99277 · Runtime
NO FIX YET
A race in the Linux kernel's ksmbd SMB server lets a connection be freed while another session reference still uses it. The sources do not state what an attacker gets beyond a crash or memory misuse in the kernel.
first public Nov 7, 2026 · 1 source
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Only systems running the Linux kernel's ksmbd SMB server are exposed, since it is the code path that registers session channels. Machines that do not load ksmbd, or that run Samba instead, can skip it. The sources do not say which kernel versions are affected.
Not affected if ksmbd-not-loaded, samba-only
Who cares file-server, kernel, ksmbd, linux, smb
grep -i ksmbd /boot/config-$(uname -r) (CONFIG_SMB_SERVER set)lsmod | grep ksmbdUnknown from the sources.
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: hold a connection reference for each session channel
ksmbd_session_unregister() removes a session from the global and per- connection tables before dropping the table reference. A concurrent reference holder can keep the session and its channel list alive after those removals.
Connection cleanup can no longer find the unpublished session to remove its channels. Since a channel only stores a raw conn pointer, the connection can be freed while another session reference holder is still accessing it, for example during SMB3.1.1 binding or a procfs read.
Take a connection reference when registering a channel and release it on insertion failure, channel removal, or final session destruction. Keep the channels and signing keys until the session is destroyed so a response can still be signed after the session has been unregistered.
NVD data is provided by NIST and is public domain. Posts quoted belong to their authors.
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