CVE-2026-64394 ksmbd: add a WRITE_DAC/WRITE_OWNER check to SMB2 SET_INFO SECURITY

In the Linux kernel, the following vulnerability has been resolved: ksmbd: add a WRITEDAC/WRITEOWNER check to SMB2 SETINFO SECURITY commit cc57232cae23 "ksmbd: fix FSCTL permission bypass by adding a permission check for FSCTLSETSPARSE" added a fp-daccess gate to fsctlsetsparse and noted that...

CVE-2026-64394

Summary: CVE-2026-64394 relates to the Linux kernel ksmbd SMB2 SET_INFO SECURITY path. The fix adds a per-handle access gate to prevent rewriting security descriptors when the handle lacks WRITE_DAC/WRITE_OWNER. Previously, SMB2_SET_INFO with InfoType SMB2_O_INFO_SECURITY could re-permission a fi...

CVE-2026-64383

CVE-2026-64383 affects the Linux kernel’s SMB2 client path, specifically the SMB2_flush() replay handling. The issue arises when a replayable flush response is received and a retry fails before a replacement response is stored, causing a second free of the stale buffer due to persistent bookkeepi...

CVE-2026-64383

In the Linux kernel, the following vulnerability has been resolved: smb: client: fix double-free in SMB2flush replay SMB2flush keeps its response buffer bookkeeping across replay attempts. If a replayable flush response is received and the retry then fails before cifssendrecv stores a replacement...

CVE-2026-64257

CVE-2026-64257 affects the Linux kernel SMB2 client logic. The issue arose from overlap handling in __smb2_calc_size(), where clearing data_length could cause an invalid SMB2 response to appear as if it has no data area, allowing an unintended length-exemption path. The fix tracks data area overl...

Linux Distros Unpatched Vulnerability : CVE-2026-64394

"The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available. - ksmbd: add a WRITEDAC/WRITEOWNER check to SMB2 SETINFO SECURITY commit cc57232cae23 ksmbd: fix FSCTL permission bypass by adding a permission check for...

PT-2026-64617

Name of the Vulnerable Software and Affected Versions Linux kernel affected versions not specified Description A use-after-free issue exists in the ksmbd component during the cancellation of deferred locks in the SMB2 LOCK path. When a blocking byte-range lock request is deferred, the system...

PT-2026-64603

Name of the Vulnerable Software and Affected Versions Linux kernel affected versions not specified Description A double-free issue exists in the SMB client. A response-bearing attempt can return a replayable error and free its response buffer. If the SMB2 open init function fails before the...

CVE-2026-53383

A flaw was found in the Linux kernel's ksmbd component. A remote attacker can trigger a NULL pointer dereference by sending a specially crafted compound SMB2 request. This occurs because the session validation logic for non-first operations in a compound request does not properly check the sessio...

CVE-2026-63909 ksmbd: OOB read regression in smb_check_perm_dacl() ACE-walk loops

In the Linux kernel, the following vulnerability has been resolved: ksmbd: OOB read regression in smbcheckpermdacl ACE-walk loops Commit d07b26f39246 "ksmbd: require minimum ACE size in smbcheckpermdacl" introduced a transposed bounds check: if offsetofstruct smbace, sid + acessize size offset 2...

CVE-2026-53383

In the Linux kernel, the following vulnerability has been resolved: ksmbd: reject non-VALID session in compound request branch smb2checkusersession takes a shortcut for any operation that is not the first in a COMPOUND request: it reuses work-sess the session bound by the first operation and...

CVE-2026-53383

In the Linux kernel, the following vulnerability has been resolved: ksmbd: reject non-VALID session in compound request branch smb2checkusersession takes a shortcut for any operation that is not the first in a COMPOUND request: it reuses work-sess the session bound by the first operation and...

The vulnerability of the smb2_set_ea() function in the fs/smb/server/smb2pdu.c module, which is part of the SMB server support in Linux kernel, allows a hacker to cause a service failure.

The vulnerability of the smb2setea function in the fs/smb/server/smb2pdu.c module of the SMB server implementation in Linux operating systems is related to the copying of buffers without checking the size of the input data a classic buffer overflow attack. Exploiting this vulnerability could allo...

Astra Linux – Vulnerability in Linux 6.1

In the Linux kernel, the following vulnerability has been resolved: smb/server: The function ksmbdsessionrpcclose is called on the error path in the createsmb2pipe function. When the ksmbdiovpinrsp function fails, we should call ksmbdsessionrpcclose...

Astra Linux – Vulnerability in Linux 6.1

In the Linux kernel, the following vulnerability has been resolved: ksmbd: Fixed an infinite loop caused by resetting nextsmb2rcvhdroff during error paths. The issue occurs when a signed request fails the smb2 signature verification check. In processrequest, if checksignreq returns an error,...

kernel: smb/client: fix out-of-bounds read in smb2_compound_op()

A flaw was found in the Linux kernel's Server Message Block SMB client. A remote attacker, acting as a malicious SMB server, could send a specially crafted, truncated response with an oversized buffer length. This could lead to an out-of-bounds read in the smb2compoundop function, allowing the...

The vulnerability of the smb2_sess_setup() function in the fs/smb/server/smb2pdu.c module, which is part of the SMB server support in Linux kernel, allows a hacker to cause a service failure.

The vulnerability of the smb2sesssetup function in the fs/smb/server/smb2pdu.c module of the SMB server module in Linux operating systems is related to errors during the update of the link counters. Exploiting this vulnerability can allow an attacker to cause a service failure...

Important: kernel security, bug fix, and enhancement update

The kernel packages contain the Linux kernel, the core of any Linux operating system. Security Fixes: kernel: fs/smb/client: fix out-of-bounds read in cifssanitizeprepath CVE-2026-43112 kernel: net: mana: Fix double destroyworkqueue on service rescan PCI path CVE-2026-43276 kernel: Linux kernel:...

The vulnerability of the smb2_read() function in the fs/smb/server/smb2pdu.c module of the SMB server support module in the Linux operating system allows a hacker to cause a service failure.

The vulnerability of the smb2read function in the fs/smb/server/smb2pdu.c module of the SMB server module in the Linux operating system is related to improper memory release memory leak. Exploiting this vulnerability can allow an attacker to cause a service failure...

CVE-2026-53271

A flaw was found in the ksmbd component of the Linux kernel. A remote attacker could exploit a NULL-dereference vulnerability in the oplock/lease break notifiers. This occurs because opinfo-conn is read without proper checks, allowing a concurrent Server Message Block SMB2 LOGOFF to set op-conn t...