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A flaw was found in Samba. A remote attacker can exploit a misconfiguration in Samba file servers and classic domain controllers that use the "check… (CVE-2026-4408)

0
Critical
Published: 05/28/2026 (05/28/2026, 09:31:19 UTC)
Source: GCVE Database

Description

A flaw was found in Samba. A remote attacker can exploit a misconfiguration in Samba file servers and classic domain controllers that use the "check password script" feature. If this script is configured with the %u substitution character, the client-controlled username is passed without proper escaping of shell meta-characters. This vulnerability allows an attacker to achieve remote command execution on the affected system. This issue primarily affects non-standard configurations where the "check password script" is used with %u and the samba-dcerpcd service is started as a system service.

CVSS v3.1

Score 9.0critical

Attack Vector
Network
Attack Complexity
High
Privileges Required
None
User Interaction
None
Scope
Changed
Confidentiality
High
Integrity
High
Availability
High
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H

Affected software

Affected versions
Red HatRed Hat OpenShift EnterpriseRed Hat OpenShift Container Platform 4.20aarch64rhcos-aarch64-4.20.9.6.202606241928-0Red Hat Enterprise LinuxRed Hat Enterprise Linux BaseOS AUS (v.8.4)Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.4)x86_64Red Hat Enterprise Linux Server (v. 7 ELS)Red Hat Enterprise Linux Server Optional (v. 7 ELS)Red Hat Enterprise Linux Server ResilientStorage (v. 7 ELS)Red Hat OpenShift Container Platform 4.21rhcos-aarch64-4.21.9.6.202606241859-0

AI-Powered Analysis

Machine-generated threat intelligence

AILast updated: 07/10/2026, 11:55:59 UTC

Technical Analysis

This advisory covers security updates for Red Hat OpenShift Container Platform 4.20 and 4.21.22 that fix multiple vulnerabilities. The primary issues include a remote code execution vulnerability in Samba's SAMR protocol (CVE-2026-4408) and a kernel vulnerability related to net/sched act_pedit (CVE-2026-46331). The Samba vulnerability allows remote attackers to execute arbitrary code, while the kernel issue involves extending the writable skb range per key. Red Hat has released updated container images and RPM packages to address these vulnerabilities. Users should upgrade their OpenShift clusters to these updated versions to mitigate the risks.

Potential Impact

Successful exploitation of CVE-2026-4408 could allow remote code execution with high impact on confidentiality, integrity, and availability. The kernel vulnerability CVE-2026-46331 also impacts system stability and security. Both vulnerabilities pose significant risks to affected OpenShift Container Platform deployments if left unpatched.

Mitigation Recommendations

Red Hat has released updated container images and RPM packages that fix these vulnerabilities. Users of OpenShift Container Platform 4.20 and 4.21.22 should upgrade to these updated versions as soon as they are available in their release channels. Upgrades can be performed using the OpenShift CLI (oc) or the web console. Detailed upgrade instructions are provided in the official Red Hat documentation. Patch status is confirmed as fixed in these updated releases.

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Technical Details

Gcve Source
db.gcve.eu
Csaf Category
csaf_security_advisory
Csaf Version
2.0
Publisher
Red Hat Product Security
Advisory Id
RHSA-2026:28058
Cve Count
2
Additional Cves
["CVE-2026-4480"]
Cvss Version
3.1
State
PUBLISHED

Threat ID: 6a3aab54eed863c81e3a3a37

Added to database: 06/23/2026, 15:50:44 UTC

Last enriched: 07/10/2026, 11:55:59 UTC

Last updated: 09/23/2026, 01:47:43 UTC

Views: 187

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