CVE-2026-64399

CVE CVE-2026-64399EUVD EUVD-2026-48943Published 2026-07-25T08:50:42.000ZLast changed 2026-08-05T12:41:37.000ZCVSS 9.8

What the advisory describes

In the Linux kernel, the following vulnerability has been resolved: ksmbd: add permission checks for FSCTL_DUPLICATE_EXTENTS_TO_FILE The FSCTL_DUPLICATE_EXTENTS_TO_FILE arm of smb2_ioctl() overwrites the destination file's data via vfs_clone_file_range() with neither the share-level KSMBD_TREE_CONN_FLAG_WRITABLE check nor a per-handle fp->daccess check that the other write-bearing arms carry. A client can overwrite destination data on a read-only share, or from a handle opened with only FILE_WRITE_ATTRIBUTES (which still yields an FMODE_WRITE filp). FILE_WRITE_ATTRIBUTES-only destination handle overwrote the file's data via the clone. Add both checks, matching the FSCTL_SET_SPARSE permission fix; require FILE_WRITE_DATA since this writes data.

Source: EUVD (ENISA), in the words of the advisory.

Products the advisory names

These come from the advisory itself, not from any check we performed.

Linux — Linux patch: 7.1.4; eb817368f50c1cbe1bd07044124aad7db6330e3a <620d133d469295ee7c017ca6aafac335f65c4a5a; eb817368f50c1cbe1bd07044124aad7db6330e3a <c917e4522d251071dde9871b9142d8ea1186ebfe; patch: 6.6.145; patch: 0; 5.15; eb817368f50c1cbe1bd07044124aad7db6330e3a <388e4139db27a9e3612c9d356b826f5b1ff6a9e3; eb817368f50c1cbe1bd07044124aad7db6330e3a <baae7b39673ec21073a25e3d14f8feaada01d5df; patch: 6.12.96; patch: 6.18.39; patch: 6.1.178; eb817368f50c1cbe1bd07044124aad7db6330e3a <9b9cf7e65cbeaae1b6636144bacee611cdd7a5d6; patch: 7.2-rc1; eb817368f50c1cbe1bd07044124aad7db6330e3a <bf460ad5958d506492de4524a656439da3f99c51

The versions shown are the advisory's own. Patchlage compares no version numbers and derives no judgement from them — which version is installed is something a person has to look up.

Carried in the product catalogue

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Linux — Linux

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