CVE-2026-1933: Samba: missing access check on reparse point operations

Severity: medium (CVSS 6.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.9% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-05-27 · updated 2026-10-30
Weakness: CWE-284

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.

Affected products

Red Hat Enterprise Linux: 7.0, 8.0, 9.0, 10.0 (and their updates)
Red Hat OpenShift Container Platform 4.18: 4.0 (and their updates)
Samba: from 4.1.0 before 4.2.2 — fixed in 4.2.2
Red Hat OpenShift Container Platform 4.18: all versions — fixed in 418.94.202608142238-0
Red Hat Enterprise Linux 10: all versions — fixed in 0:4.23.5-109.el10_2
Red Hat Enterprise Linux 10.0 Extended Update Support: all versions — fixed in 0:4.21.3-114.el10_0.1
Red Hat Enterprise Linux 7: all versions
Red Hat Enterprise Linux 8: all versions — fixed in 0:4.19.4-16.el8_10
Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support: all versions — fixed in 0:4.15.5-16.el8_6.1
Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On: all versions — fixed in 0:4.15.5-16.el8_6.1
Red Hat Enterprise Linux 8.8 Telecommunications Update Service: all versions — fixed in 0:4.17.5-7.el8_8.1
Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions: all versions — fixed in 0:4.17.5-7.el8_8.1
Red Hat Enterprise Linux 9: all versions — fixed in 0:4.23.5-10.el9_8
Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions: all versions — fixed in 0:4.17.5-105.el9_2.5
Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions: all versions — fixed in 0:4.19.4-105.el9_4.4
Red Hat Enterprise Linux 9.6 Extended Update Support: all versions — fixed in 0:4.21.3-14.el9_6.1
Red Hat OpenShift Container Platform 4.12: all versions — fixed in 412.86.202608241157-0
Red Hat OpenShift Container Platform 4.13: all versions — fixed in 413.92.202609080414-0
Red Hat OpenShift Container Platform 4.14: all versions — fixed in 414.92.202608172040-0
Red Hat OpenShift Container Platform 4.15: all versions — fixed in 415.92.202608180329-0
Red Hat OpenShift Container Platform 4.16: all versions — fixed in 416.94.202608150307-0
Red Hat OpenShift Container Platform 4.17: all versions — fixed in 417.94.202608250221-0
Red Hat OpenShift Container Platform 4.19: all versions — fixed in 4.19.9.6.202606241344-0
Red Hat OpenShift Container Platform 4.20: all versions — fixed in 4.20.9.6.202608121719-0
Red Hat OpenShift Container Platform 4.21: all versions — fixed in 4.21.9.6.202608122143-0
Red Hat OpenShift Container Platform 4.22: all versions — fixed in 4.22.9.8.202608130832-0
Red Hat OpenShift Container Platform 5: all versions

How to fix

Upgrade to a fixed version: Samba 4.2.2; Red Hat OpenShift Container Platform 4.18 418.94.202608142238-0; Red Hat Enterprise Linux 10 0:4.23.5-109.el10_2; Red Hat Enterprise Linux 10.0 Extended Update Support 0:4.21.3-114.el10_0.1; Red Hat Enterprise Linux 8 0:4.19.4-16.el8_10; Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support 0:4.15.5-16.el8_6.1; Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On 0:4.15.5-16.el8_6.1; Red Hat Enterprise Linux 8.8 Telecommunications Update Service 0:4.17.5-7.el8_8.1; Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions 0:4.17.5-7.el8_8.1; Red Hat Enterprise Linux 9 0:4.23.5-10.el9_8; Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions 0:4.17.5-105.el9_2.5; Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions 0:4.19.4-105.el9_4.4. Check the vendor advisory for mitigations.

References

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