Answer in brief
CVE-2026-64399 records a Unknown severity vulnerability in ksmbd: add permission checks for FSCTL_DUPLICATE_EXTENTS_TO_FILE. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=eb817368f50c1cbe1bd07044124aad7db6330e3a <bf460ad5958d506492de4524a656439da3f99c51 || >=eb817368f50c1cbe1bd07044124aad7db6330e3a <620d133d469295ee7c017ca6aafac335f65c4a5a || >=eb817368f50c1cbe1bd07044124aad7db6330e3a <9b9cf7e65cbeaae1b6636144bacee611cdd7a5d6 || >=eb817368f50c1cbe1bd07044124aad7db6330e3a <baae7b39673ec21073a25e3d14f8feaada01d5df || >=eb817368f50c1cbe1bd07044124aad7db6330e3a <c917e4522d251071dde9871b9142d8ea1186ebfe || >=eb817368f50c1cbe1bd07044124aad7db6330e3a <388e4139db27a9e3612c9d356b826f5b1ff6a9e3 | bf460ad5958d506492de4524a656439da3f99c51, 620d133d469295ee7c017ca6aafac335f65c4a5a, 9b9cf7e65cbeaae1b6636144bacee611cdd7a5d6, baae7b39673ec21073a25e3d14f8feaada01d5df, c917e4522d251071dde9871b9142d8ea1186ebfe, 388e4139db27a9e3612c9d356b826f5b1ff6a9e3 |
| Linux/Linuxgeneric | 5.15 | Not reported |
Published upstream
Jul 25, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 5, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 5, 2026
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.
Quoted source text, attributed separately from HOL analysis.
Answer in brief
CVE-2026-64399 records a Unknown severity vulnerability in ksmbd: add permission checks for FSCTL_DUPLICATE_EXTENTS_TO_FILE. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=eb817368f50c1cbe1bd07044124aad7db6330e3a <bf460ad5958d506492de4524a656439da3f99c51 || >=eb817368f50c1cbe1bd07044124aad7db6330e3a <620d133d469295ee7c017ca6aafac335f65c4a5a || >=eb817368f50c1cbe1bd07044124aad7db6330e3a <9b9cf7e65cbeaae1b6636144bacee611cdd7a5d6 || >=eb817368f50c1cbe1bd07044124aad7db6330e3a <baae7b39673ec21073a25e3d14f8feaada01d5df || >=eb817368f50c1cbe1bd07044124aad7db6330e3a <c917e4522d251071dde9871b9142d8ea1186ebfe || >=eb817368f50c1cbe1bd07044124aad7db6330e3a <388e4139db27a9e3612c9d356b826f5b1ff6a9e3 | bf460ad5958d506492de4524a656439da3f99c51, 620d133d469295ee7c017ca6aafac335f65c4a5a, 9b9cf7e65cbeaae1b6636144bacee611cdd7a5d6, baae7b39673ec21073a25e3d14f8feaada01d5df, c917e4522d251071dde9871b9142d8ea1186ebfe, 388e4139db27a9e3612c9d356b826f5b1ff6a9e3 |
| Linux/Linuxgeneric | 5.15 | Not reported |
Published upstream
Jul 25, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 5, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 5, 2026
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.
Quoted source text, attributed separately from HOL analysis.