Answer in brief
CVE-2026-64388 records a Unknown severity vulnerability in smb/client: fix chown/chgrp with SMB3 POSIX Extensions. 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 | >=b326614ea2159ea5c835d320f261d05d080cd201 <550cfb8a81181331d4d0f76ab75ee58a0bf41e3e || >=b326614ea2159ea5c835d320f261d05d080cd201 <760ef2c579c2609cf17fb1cd5392f64d42d43d33 | 550cfb8a81181331d4d0f76ab75ee58a0bf41e3e, 760ef2c579c2609cf17fb1cd5392f64d42d43d33 |
| Linux/Linuxgeneric | 4.18 | 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: smb/client: fix chown/chgrp with SMB3 POSIX Extensions Ownership (chown) and group (chgrp) modifications were being ignored when mounting with SMB3 POSIX Extensions unless CIFS_MOUNT_CIFS_ACL or CIFS_MOUNT_MODE_FROM_SID were also explicitly set. Fix this by checking for posix_extensions in cifs_setattr_nounix() when updating UID and GID, ensuring that id_mode_to_cifs_acl() is called to map and set the ownership/group information on the server.
Quoted source text, attributed separately from HOL analysis.
Answer in brief
CVE-2026-64388 records a Unknown severity vulnerability in smb/client: fix chown/chgrp with SMB3 POSIX Extensions. 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 | >=b326614ea2159ea5c835d320f261d05d080cd201 <550cfb8a81181331d4d0f76ab75ee58a0bf41e3e || >=b326614ea2159ea5c835d320f261d05d080cd201 <760ef2c579c2609cf17fb1cd5392f64d42d43d33 | 550cfb8a81181331d4d0f76ab75ee58a0bf41e3e, 760ef2c579c2609cf17fb1cd5392f64d42d43d33 |
| Linux/Linuxgeneric | 4.18 | 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: smb/client: fix chown/chgrp with SMB3 POSIX Extensions Ownership (chown) and group (chgrp) modifications were being ignored when mounting with SMB3 POSIX Extensions unless CIFS_MOUNT_CIFS_ACL or CIFS_MOUNT_MODE_FROM_SID were also explicitly set. Fix this by checking for posix_extensions in cifs_setattr_nounix() when updating UID and GID, ensuring that id_mode_to_cifs_acl() is called to map and set the ownership/group information on the server.
Quoted source text, attributed separately from HOL analysis.