CVE-2026-1933

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Last Modified: UTC

Important Important severity What does this mean?
7.1 CVSS v3 Score Breakdown

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.

Statement

This vulnerability is rated Important severity by Red Hat Product Security, because authenticated users with filesystem-level write permissions may bypass Samba’s SMB-layer read-only protections for reparse point operations.

The flaw affects shares configured with "read only = yes", where Samba failed to properly enforce access checks when setting or deleting reparse point metadata. An attacker with existing write permissions on the underlying filesystem may manipulate SMB reparse point metadata to alter how files are presented to SMB clients, including converting files into symbolic links.

The vulnerability does not bypass underlying filesystem access controls or grant additional operating system privileges. However, successful exploitation may significantly disrupt file access for users of the affected share, including making large portions of a shared filesystem unavailable through widespread reparse point modification. Because the attack requires authenticated access and existing filesystem write permissions, Privileges Required are assessed as Low (PR:L).


This vulnerability affects Samba versions beginning with the introduction of NTFS-style reparse point support in Samba 4.21.

Mitigation

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.

Additional information

External References

Affected Packages and Issued Red Hat Security Errata

Unless explicitly stated as not affected, all previous versions of packages in any minor update stream of a product listed here should be assumed vulnerable, although may not have been subject to full analysis.

Products / Services Components State Errata
Red Hat Enterprise Linux 10 samba Fixed RHSA-2026:22963
Red Hat Enterprise Linux 10.0 Extended Update Support samba Fixed RHSA-2026:28055
Red Hat Enterprise Linux 6 samba Out of support scope
Red Hat Enterprise Linux 6 samba4 Out of support scope
Red Hat Enterprise Linux 7 samba Will not fix
Red Hat Enterprise Linux 8 samba Fixed RHSA-2026:22644
Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support samba Fixed RHSA-2026:28057
Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On samba Fixed RHSA-2026:28057
Red Hat Enterprise Linux 8.8 Telecommunications Update Service samba Fixed RHSA-2026:28056
Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions samba Fixed RHSA-2026:28056

Common Vulnerability Scoring System (CVSS) Score Details

Important note

CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authorities (CNA) source for its products and services (see Red Hat classifications ).

CVSS v3 Score Breakdown

Red Hat NVD cve.org
CVSS v3 Base Score 7.1 6.5 7.1
Attack Vector Network Network Network
Attack Complexity Low Low Low
Privileges Required Low Low Low
User Interaction None None None
Scope Unchanged Unchanged Unchanged
Confidentiality Impact None None None
Integrity Impact Low High Low
Availability Impact High None High

CVSS v3 Vector

Red Hat CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:H

NVD CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N

cve.org CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:H

Acknowledgements

Red Hat would like to thank Asim Viladi Oglu Manizada for reporting this issue.

Frequently Asked Questions

Why is Red Hat's CVSS v3 score or Impact different from other vendors?

 For open source software shipped by multiple vendors, the CVSS base scores may vary for each vendor's version depending on the version they ship, how they ship it, the platform, and even how the software is compiled. This makes scoring of vulnerabilities difficult for third-party vulnerability databases such as NVD that only provide a single CVSS base score for each vulnerability. Red Hat scores reflect how a vulnerability affects our products specifically.

For more information, see https://access.redhat.com/solutions/762393.

My product is listed as "Under investigation" or "Affected", when will Red Hat release a fix for this vulnerability?
  • "Under investigation" doesn't necessarily mean that the product is affected by this vulnerability. It only means that our Analysis Team is still working on determining whether the product is affected and how it is affected.
  • "Affected" means that our Analysis Team has determined that this product is affected by this vulnerability and might release a fix to address this in the near future.

What can I do if my product is listed as "Will not fix"?

 A "will not fix" status means that a fix for an affected product version is not planned or not possible due to complexity, which may create additional risk.

Available options depend mostly on the Impact of the vulnerability and the current Life Cycle phase of your product. Overall, you have the following options:
  • Upgrade to a supported product version that includes a fix for this vulnerability (recommended).
  • Apply a mitigation (if one exists).
  • Open a This content is not included.support case to request a prioritization of releasing a fix for this vulnerability.

What can I do if my product is listed as "Fix deferred"?

 A deferred status means that a fix for an affected product version is not guaranteed due to higher-priority development work.

Available options depend mostly on the Impact of the vulnerability and the current Life Cycle phase of your product. Overall, you have the following options:
  • Apply a mitigation (if one exists).
  • Open a This content is not included.support case to request a prioritization of releasing a fix for this vulnerability.
  • Red Hat Engineering focuses on addressing high-priority issues based on their complexity or limited lifecycle support. Therefore, lower-priority issues will not receive immediate fixes.

What is a mitigation?

 A mitigation is an action that can be taken to reduce the impact of a security vulnerability, without deploying any fixes.

I have a Red Hat product but it is not in the above list, is it affected?

 The listed products were found to include one or more of the components that this vulnerability affects. These products underwent a thorough evaluation to determine their affectedness by this vulnerability. Note that layered products (such as container-based offerings) that consume affected components from any of the products listed in this table may be affected and are not represented.

Why is my security scanner reporting my product as vulnerable to this vulnerability even though my product version is fixed or not affected?

 In order to maintain code stability and compatibility, Red Hat usually does not rebase packages to entirely new versions. Instead, we backport fixes and new features to an older version of the package we distribute. This can result in some security scanners that only consider the package version to report the package as vulnerable. To avoid this, we suggest that you use an approved vulnerability scanner from our This content is not included.Red Hat Vulnerability Scanner Certification program.

My product is listed as "Out of Support Scope". What does this mean?

 When a product is listed as "Out of Support Scope", it means a vulnerability with the impact level assigned to this CVE is no longer covered by its current support lifecycle phase. The product has been identified to contain the impacted component, but analysis to determine whether it is affected or not by this vulnerability was not performed. The product should be assumed to be affected. Customers are advised to apply any mitigation options documented on this page, consider removing or disabling the impacted component, or upgrade to a supported version of the product that has an update available.