Samba: missing access check on reparse point operations
Summary
| CVE | CVE-2026-1933 |
|---|---|
| State | PUBLISHED |
| Assigner | redhat |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-05-27 14:16:44 UTC |
| Updated | 2026-06-23 08:16:24 UTC |
| Description | A flaw was found in Samba’s handling of NTFS-style reparse points on shares configured with read only = yes. Due to missing SMB-layer access checks, authenticated users with underlying filesystem write permissions may create or delete reparse point metadata through SMB operations even on read-only exports. This could allow modification of SMB-visible file behavior, including converting files into symbolic links or other reparse point types. |
Risk And Classification
Primary CVSS: v3.1 6.5 MEDIUM from [email protected]
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
EPSS: 0.005230000 probability, percentile 0.401150000 (date 2026-06-22)
Problem Types: CWE-284 | NVD-CWE-noinfo | CWE-284 Improper Access Control
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | [email protected] | Primary | 6.5 | MEDIUM | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N |
| 3.1 | [email protected] | Secondary | 7.1 | HIGH | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:H |
| 3.1 | CNA | CVSS | 7.1 | HIGH | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:H |
CVSS v3.1 Breakdown
Attack Vector
NetworkAttack Complexity
LowPrivileges Required
LowUser Interaction
NoneScope
UnchangedConfidentiality
NoneIntegrity
HighAvailability
NoneCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
NVD Known Affected Configurations (CPE 2.3)
| Type | Vendor | Product | Version | Update | Edition | Language |
|---|---|---|---|---|---|---|
| Operating System | Redhat | Enterprise Linux | 10.0 | All | All | All |
| Operating System | Redhat | Enterprise Linux | 7.0 | All | All | All |
| Operating System | Redhat | Enterprise Linux | 8.0 | All | All | All |
| Operating System | Redhat | Enterprise Linux | 9.0 | All | All | All |
| Application | Redhat | Openshift Container Platform | 4.0 | All | All | All |
| Application | Samba | Samba | All | All | All | All |
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Red Hat | Red Hat Enterprise Linux 10 | unaffected 0:4.23.5-109.el10_2 * rpm | Not specified |
| CNA | Red Hat | Red Hat Enterprise Linux 10.0 Extended Update Support | unaffected 0:4.21.3-114.el10_0.1 * rpm | Not specified |
| CNA | Red Hat | Red Hat Enterprise Linux 8 | unaffected 0:4.19.4-16.el8_10 * rpm | Not specified |
| CNA | Red Hat | Red Hat Enterprise Linux 8 | unaffected 0:4.19.4-16.el8_10 * rpm | Not specified |
| CNA | Red Hat | Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support | unaffected 0:4.15.5-16.el8_6.1 * rpm | Not specified |
| CNA | Red Hat | Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On | unaffected 0:4.15.5-16.el8_6.1 * rpm | Not specified |
| CNA | Red Hat | Red Hat Enterprise Linux 8.8 Telecommunications Update Service | unaffected 0:4.17.5-7.el8_8.1 * rpm | Not specified |
| CNA | Red Hat | Red Hat Enterprise Linux 8.8 Update Services For SAP Solutions | unaffected 0:4.17.5-7.el8_8.1 * rpm | Not specified |
| CNA | Red Hat | Red Hat Enterprise Linux 9 | unaffected 0:4.23.5-10.el9_8 * rpm | Not specified |
| CNA | Red Hat | Red Hat Enterprise Linux 9 | unaffected 0:4.23.5-10.el9_8 * rpm | Not specified |
| CNA | Red Hat | Red Hat Enterprise Linux 9.2 Update Services For SAP Solutions | unaffected 0:4.17.5-105.el9_2.5 * rpm | Not specified |
| CNA | Red Hat | Red Hat Enterprise Linux 9.4 Update Services For SAP Solutions | unaffected 0:4.19.4-105.el9_4.4 * rpm | Not specified |
| CNA | Red Hat | Red Hat Enterprise Linux 9.6 Extended Update Support | unaffected 0:4.21.3-14.el9_6.1 * rpm | Not specified |
| CNA | Red Hat | Red Hat Enterprise Linux 6 | Not specified | Not specified |
| CNA | Red Hat | Red Hat Enterprise Linux 6 | Not specified | Not specified |
| CNA | Red Hat | Red Hat Enterprise Linux 7 | Not specified | Not specified |
| CNA | Red Hat | Red Hat OpenShift Container Platform 4 | Not specified | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| access.redhat.com/errata/RHSA-2026:28053 | [email protected] | access.redhat.com | |
| access.redhat.com/security/cve/CVE-2026-1933 | [email protected] | access.redhat.com | Third Party Advisory |
| access.redhat.com/errata/RHSA-2026:28054 | [email protected] | access.redhat.com | |
| access.redhat.com/errata/RHSA-2026:25979 | [email protected] | access.redhat.com | |
| access.redhat.com/errata/RHSA-2026:22963 | [email protected] | access.redhat.com | |
| bugzilla.redhat.com/show_bug.cgi | [email protected] | bugzilla.redhat.com | Issue Tracking, Third Party Advisory |
| access.redhat.com/errata/RHSA-2026:22644 | [email protected] | access.redhat.com | |
| access.redhat.com/errata/RHSA-2026:28055 | [email protected] | access.redhat.com | |
| access.redhat.com/errata/RHSA-2026:25049 | [email protected] | access.redhat.com | |
| bugzilla.samba.org/show_bug.cgi | [email protected] | bugzilla.samba.org | Issue Tracking, Vendor Advisory |
| access.redhat.com/errata/RHSA-2026:28056 | [email protected] | access.redhat.com | |
| access.redhat.com/errata/RHSA-2026:28057 | [email protected] | access.redhat.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: Red Hat would like to thank Asim Viladi Oglu Manizada for reporting this issue. (en)
Additional Advisory Data
| Source | Time | Event |
|---|---|---|
| CNA | 2026-03-13T08:29:39.852Z | Reported to Red Hat. |
| CNA | 2026-05-27T12:08:33.095Z | Made public. |
Workarounds
CNA: Administrators can mitigate this issue by ensuring users who access a read only = yes Samba share do not have filesystem-level write permission to the exported files. A server administrator may also monitor and remove unintended "user.SmbReparse" xattr (extended attributes) and the associated FILE_ATTRIBUTE_REPARSE_POINT "user.DosAttrib" bit metadata if exploitation is suspected.
There are currently no legacy QID mappings associated with this CVE.