CVE-2025-9640

Samba: vfs_streams_xattr uninitialized memory write possible

Published Oct 15, 2025 CVSS 3.1 · 4.3 Medium EPSS < 1% KEV · Not listed
Description
A flaw was found in Samba, in the vfs_streams_xattr module, where uninitialized heap memory could be written into alternate data streams. This allows an authenticated user to read residual memory content that may include sensitive data, resulting in an information disclosure vulnerability.

Remediation

Vendor Workaround

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.

Tracking

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Advisories

Source ID Title
Debian DLA Debian DLA DLA-4384-1 samba security update
Ubuntu USN Ubuntu USN USN-7826-1 Samba vulnerabilities
Ubuntu USN Ubuntu USN USN-7826-2 Samba vulnerabilities
History
Type Values Removed Values Added
First Time appeared Redhat rhel Els
CPEs cpe:/o:redhat:enterprise_linux:10
cpe:/o:redhat:enterprise_linux:6
cpe:/o:redhat:enterprise_linux:7
cpe:/o:redhat:enterprise_linux:8
cpe:/o:redhat:enterprise_linux:9
cpe:/a:redhat:enterprise_linux:10
cpe:/a:redhat:enterprise_linux:8
cpe:/a:redhat:enterprise_linux:9
cpe:/o:redhat:rhel_els:6
cpe:/o:redhat:rhel_els:7
Vendors & Products Redhat rhel Els
Type Values Removed Values Added
CPEs cpe:/o:redhat:rhivos:1
Vendors & Products Redhat rhivos
Type Values Removed Values Added
First Time appeared Redhat rhivos
CPEs cpe:/o:redhat:rhivos:1
Vendors & Products Redhat rhivos
Type Values Removed Values Added
Weaknesses CWE-908
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description A flaw was found in Samba, in the vfs_streams_xattr module, where uninitialized heap memory could be written into alternate data streams. This allows an authenticated user to read residual memory content that may include sensitive data, resulting in an information disclosure vulnerability.
Title Samba: vfs_streams_xattr uninitialized memory write possible
First Time appeared Redhat
Redhat enterprise Linux
Redhat openshift
CPEs cpe:/a:redhat:openshift:4
cpe:/o:redhat:enterprise_linux:10
cpe:/o:redhat:enterprise_linux:6
cpe:/o:redhat:enterprise_linux:7
cpe:/o:redhat:enterprise_linux:8
cpe:/o:redhat:enterprise_linux:9
Vendors & Products Redhat
Redhat enterprise Linux
Redhat openshift
References
Metrics cvssV3_1

{'score': 4.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
redhat
Published
Updated
Nov 6, 2026, 5:47 PM
Reserved
Aug 29, 2025, 3:11 AM
Status
Deferred
Published
Oct 15, 2025, 1:16 PM
Modified
Nov 6, 2026, 6:17 PM
Severity
Important
Public date
Oct 15, 2025, 12:45 PM