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

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.

Published: 2026-05-27 Last update: 2026-06-02 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2026-1933 is rated Low Risk (31.4/100): CVSS High severity, with low exploitation likelihood (EPSS 0.03%). Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-1933

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-28 0.03%

Full EPSS history (1 record total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-1933

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.1 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
2.8 4.2 [email protected]
6.5 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:N)
Service keeps running; no real outage angle.
2.8 3.6 [email protected]

Weakness enumeration for CVE-2026-1933

GitHub Security Advisory for CVE-2026-1933

GHSA-c866-5hw6-cqf9 · Severity: high — A flaw was found in Samba’s handling of NTFS-style reparse points on shares configured with read...

OS Trackers for CVE-2026-1933

vendor priority summary link
debian unimportant CVE-2026-1933 unimportant priority: Debian including 1 source packages (samba), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2026-1933
redhat high https://access.redhat.com/security/cve/CVE-2026-1933
suse high CVE-2026-1933 severity important: SUSE including 118 source package names (ctdb, ctdb-4.21.10+git.501.277ba349a01-150700.3.26.1, …), 522 product×package rows across 30 product lines (SUSE Linux Enterprise High Availability Extension 12 SP5, SUSE Linux Enterprise High Availability Extension 15 SP4, … (30 product lines)): Known Not Affected 499, Fixed 23. https://www.suse.com/security/cve/CVE-2026-1933/
ubuntu medium CVE-2026-1933 medium priority: Ubuntu including 1 source packages (samba), 9 status rows across 9 suites (bionic, focal, jammy, noble, questing, resolute, trusty, upstream, xenial): not-affected 6, released 3. https://ubuntu.com/security/CVE-2026-1933

Affected software / configurations for CVE-2026-1933

Vendor Product Version Raw CPE
redhat openshift_container_platform 4.0 cpe:2.3:a:redhat:openshift_container_platform:4.0:*:*:*:*:*:*:*
samba samba >= 4.1.0, < 4.2.2 cpe:2.3:a:samba:samba:*:*:*:*:*:*:*:*
redhat enterprise_linux 7.0 cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:*
redhat enterprise_linux 8.0 cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:*
redhat enterprise_linux 9.0 cpe:2.3:o:redhat:enterprise_linux:9.0:*:*:*:*:*:*:*
redhat enterprise_linux 10.0 cpe:2.3:o:redhat:enterprise_linux:10.0:*:*:*:*:*:*:*

References for CVE-2026-1933

URL Tags
https://access.redhat.com/security/cve/CVE-2026-1933 Third Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2447317 Issue Tracking Third Party Advisory
https://bugzilla.samba.org/show_bug.cgi?id=15992 Issue Tracking Vendor Advisory
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