UBUNTU-CVE-2026-64390

In the Linux kernel, the following vulnerability has been resolved: ksmbd: track the connection owning a byte-range lock SMB2LOCK adds each granted byte-range lock to both the file lock list and the lock list of the connection which handled the request. The final close and durable handle paths,...

EUVD-2026-48781

In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix use-after-free of a deferred filelock on SMB2CLOSE then SMB2CANCEL Commit f580d27e8928 "ksmbd: fix use-after-free of a deferred filelock on double SMB2CANCEL" made smb2cancel skip a work whose state is...

CVE-2026-64437

CVE-2026-64437 affects the ksmbd component of the Linux kernel. A use-after-free in a deferred file_lock can be triggered by a sequence of SMB2_CLOSE followed by SMB2_CANCEL, allowing an authenticated SMB client to cause a kernel crash (denial of service) via the freed file_lock. The root cause i...

CVE-2026-64437

In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix use-after-free of a deferred filelock on SMB2CLOSE then SMB2CANCEL Commit f580d27e8928 "ksmbd: fix use-after-free of a deferred filelock on double SMB2CANCEL" made smb2cancel skip a work whose state is...

CVE-2026-64398 ksmbd: add a permission check for FSCTL_SET_ZERO_DATA

In the Linux kernel, the following vulnerability has been resolved: ksmbd: add a permission check for FSCTLSETZERODATA FSCTLSETZERODATA in smb2ioctl destroys file data via ksmbdvfszerodata - vfsfallocatePUNCHHOLE/ZERORANGE after checking only the share-level KSMBDTREECONNFLAGWRITABLE, with no...

EUVD-2026-48942

In the Linux kernel, the following vulnerability has been resolved: ksmbd: add a permission check for FSCTLSETZERODATA FSCTLSETZERODATA in smb2ioctl destroys file data via ksmbdvfszerodata - vfsfallocatePUNCHHOLE/ZERORANGE after checking only the share-level KSMBDTREECONNFLAGWRITABLE, with no...

CVE-2026-64398

In the Linux kernel, the following vulnerability has been resolved: ksmbd: add a permission check for FSCTLSETZERODATA FSCTLSETZERODATA in smb2ioctl destroys file data via ksmbdvfszerodata - vfsfallocatePUNCHHOLE/ZERORANGE after checking only the share-level KSMBDTREECONNFLAGWRITABLE, with no...

EUVD-2026-48940

In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix UAF of struct filelock in SMB2LOCK deferred-lock cancellation When a blocking byte-range lock request is deferred in the FILELOCKDEFERRED path, ksmbd registers the asynchronous work into the connection's asyncrequests...

CVE-2026-64396

In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix UAF of struct filelock in SMB2LOCK deferred-lock cancellation When a blocking byte-range lock request is deferred in the FILELOCKDEFERRED path, ksmbd registers the asynchronous work into the connection's asyncrequests...

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-2026-64394 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...

EUVD-2026-48938

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 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-2026-64383

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-2026-64383

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-2026-64257

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...

CVE-2026-64393: Undefined Security Weakness

In the Linux kernel, the following vulnerability has been resolved: ksmbd: run set info with opener credentials SMB2 SETINFO handlers call path-based VFS helpers after checking the access mask granted to the SMB handle. Those helpers perform their owner, inode permission and LSM checks using the...

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...

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-2026-64603

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...