CVE-2026-43001

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Last Modified: UTC

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

Description

A flaw was found in OpenStack Keystone. An attacker holding an unrestricted application credential could exploit a vulnerability in the POST /v3/credentials endpoint where the caller-supplied project_id for an EC2-type credential was not validated against the project of the authenticating application credential. This allows the attacker to create an EC2 credential targeting a different project. Subsequently, a /v3/ec2tokens exchange would issue a Keystone token scoped to the targeted project, enabling unauthorized cross-project access and lateral movement within the credential owner's role footprint.

Statement

This flaw in OpenStack Keystone allows an attacker with an unrestricted application credential to bypass project isolation. By exploiting improper validation during EC2 credential creation, an attacker can gain unauthorized access and move laterally between projects within a Red Hat OpenStack Platform deployment, compromising multi-tenant security. If the roles from the original project the attacker holds a credential are compatible with the roles in the project the attacker is targeting, the attacker can perform the same actions granted permission from the initial project in the targeted project. Depending on the level of privileges the attacker has that means a high impact for confidentiality, availability and integrity.

Mitigation

To reduce exposure, ensure that OpenStack application credentials are created with the most restrictive scope possible, limiting their permissions to only what is essential for their intended function. If EC2 credentials are not actively used within your OpenStack deployment, consider disabling the EC2 credential API endpoint in Keystone to prevent unauthorized creation of cross-project EC2 credentials. Refer to the OpenStack Keystone administration guide for detailed instructions on managing application credential scopes and disabling API endpoints. Any changes to Keystone configuration may require a service restart to take effect.

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 OpenStack Platform 13 (Queens) rhosp13/openstack-keystone Not affected
Red Hat OpenStack Platform 16.2 openstack-keystone Fixed RHSA-2026:54757
Red Hat OpenStack Platform 16.2 rhosp-rhel8/openstack-keystone Fixed RHSA-2026:54757
Red Hat OpenStack Platform 17.1 openstack-keystone Affected
Red Hat OpenStack Platform 17.1 rhosp-rhel9/openstack-keystone Not affected
Red Hat OpenStack Platform 18.0 rhoso/openstack-keystone-rhel9 Not affected
Red Hat OpenStack Services on OpenShift 18.0 openstack-keystone Fixed RHSA-2026:39808

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 8 8 8
Attack Vector Network Network Network
Attack Complexity High High High
Privileges Required High High High
User Interaction None None None
Scope Changed Changed Changed
Confidentiality Impact High High High
Integrity Impact High High High
Availability Impact High High High

CVSS v3 Vector

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

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

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

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.