Red Hat Multicluster Engine for Kubernetes Open Cluster Management certificate validation

CVSS Meta Temp Score
CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.
Current Exploit Price (≈)
Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.
CTI Interest Score
Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
6.2$0-$5k0.00

Summaryinfo

A vulnerability was found in Red Hat Multicluster Engine for Kubernetes. It has been declared as critical. Affected by this issue is some unknown functionality of the component Open Cluster Management. Executing a manipulation can lead to certificate validation. The identification of this vulnerability is CVE-2026-4740. The attack can only be executed locally. There is no exploit available.

Detailsinfo

A vulnerability has been found in Red Hat Multicluster Engine for Kubernetes (version now known) and classified as critical. This vulnerability affects some unknown processing of the component Open Cluster Management. The manipulation with an unknown input leads to a certificate validation vulnerability. The CWE definition for the vulnerability is CWE-295. The product does not validate, or incorrectly validates, a certificate. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

A flaw was found in Open Cluster Management (OCM), the technology underlying Red Hat Advanced Cluster Management (ACM). Improper validation of Kubernetes client certificate renewal allows a managed cluster administrator to forge a client certificate that can be approved by the OCM controller. This enables cross-cluster privilege escalation and may allow an attacker to gain control over other managed clusters, including the hub cluster.

The advisory is available at access.redhat.com. This vulnerability was named CVE-2026-4740 since 03/24/2026. The exploitation appears to be easy. Local access is required to approach this attack. Additional levels of successful authentication are needed for exploitation. The technical details are unknown and an exploit is not available. The structure of the vulnerability defines a possible price range of USD $0-$5k at the moment (estimation calculated on 04/07/2026). This vulnerability is assigned to T1587.003 by the MITRE ATT&CK project.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

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Productinfo

Type

Vendor

Name

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.2
VulDB Meta Temp Score: 6.2

VulDB Base Score: 4.2
VulDB Temp Score: 4.2
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 8.2
CNA Vector (redhat): 🔒

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Certificate validation
CWE: CWE-295 / CWE-287
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: No

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: no mitigation known
Status: 🔍

0-Day Time: 🔒

Timelineinfo

03/24/2026 CVE reserved
04/07/2026 +13 days Advisory disclosed
04/07/2026 +0 days VulDB entry created
04/07/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: redhat.com

Advisory: access.redhat.com
Status: Not defined

CVE: CVE-2026-4740 (🔒)
GCVE (CVE): GCVE-0-2026-4740
GCVE (VulDB): GCVE-100-355774

Entryinfo

Created: 04/07/2026 17:59
Changes: 04/07/2026 17:59 (62)
Complete: 🔍
Cache ID: 216:EB9:103

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