CVE-2026-64397

In the Linux kernel, the following vulnerability has been resolved: ksmbd: serialize QUERYDIRECTORY requests per file smb2querydir stores a pointer to its stack-allocated private data in the ksmbdfile readdirdata. Concurrent QUERYDIRECTORY requests using the same file handle can overwrite this...

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,...

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...

UBUNTU-CVE-2026-64394

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...

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,...

CVE-2026-64400

In the Linux kernel, the following vulnerability has been resolved: ksmbd: prevent path traversal bypass by restricting caseless retry ksmbdvfspathlookup enforces LOOKUPBENEATH to restrict path resolution within the share root. When a crafted path attempts to escape the share boundary using...

CVE-2026-64395

In the Linux kernel, the following vulnerability has been resolved: ksmbd: require source read access for duplicate extents FSCTLDUPLICATEEXTENTSTOFILE passes the source file directly to vfsclonefilerange or vfscopyfilerange without checking the SMB access mask granted to the source handle. A...

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...

UBUNTU-CVE-2026-64400

In the Linux kernel, the following vulnerability has been resolved: ksmbd: prevent path traversal bypass by restricting caseless retry ksmbdvfspathlookup enforces LOOKUPBENEATH to restrict path resolution within the share root. When a crafted path attempts to escape the share boundary using...

CVE-2026-64392

In the Linux kernel, the following vulnerability has been resolved: ksmbd: use opener credentials for delete-on-close Delete-on-close can be completed by deferred or durable handle teardown, where no request work is available. Both the base-file unlink and the ADS xattr removal consequently run...

CVE-2026-64391

In the Linux kernel, the following vulnerability has been resolved: ksmbd: use opener credentials for ADS I/O Alternate data streams are stored as xattrs. Unlike regular file I/O, their read and write paths therefore call VFS xattr helpers which recheck inode permissions and LSM policy using the...

UBUNTU-CVE-2026-64399

In the Linux kernel, the following vulnerability has been resolved: ksmbd: add permission checks for FSCTLDUPLICATEEXTENTSTOFILE The FSCTLDUPLICATEEXTENTSTOFILE arm of smb2ioctl overwrites the destination file's data via vfsclonefilerange with neither the share-level KSMBDTREECONNFLAGWRITABLE che...

CVE-2026-64437 ksmbd: fix use-after-free of a deferred file_lock on SMB2_CLOSE then SMB2_CANCEL

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

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...

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-2026-64400 ksmbd: prevent path traversal bypass by restricting caseless retry

In the Linux kernel, the following vulnerability has been resolved: ksmbd: prevent path traversal bypass by restricting caseless retry ksmbdvfspathlookup enforces LOOKUPBENEATH to restrict path resolution within the share root. When a crafted path attempts to escape the share boundary using...

CVE-2026-64400

Summary (CVE-2026-64400) : In the Linux kernel’s ksmbd component, a path traversal bypass could occur due to a caseless retry bug. Specifically, __ksmbd_vfs_kern_path() could skip -EXDEV (a path traversal error) and falsely proceed to a caseless retry, permitting write-capable users to create zer...

CVE-2026-64400 ksmbd: prevent path traversal bypass by restricting caseless retry

In the Linux kernel, the following vulnerability has been resolved: ksmbd: prevent path traversal bypass by restricting caseless retry ksmbdvfspathlookup enforces LOOKUPBENEATH to restrict path resolution within the share root. When a crafted path attempts to escape the share boundary using...

EUVD-2026-48944

In the Linux kernel, the following vulnerability has been resolved: ksmbd: prevent path traversal bypass by restricting caseless retry ksmbdvfspathlookup enforces LOOKUPBENEATH to restrict path resolution within the share root. When a crafted path attempts to escape the share boundary using...