CVE-2026-22797 is an authentication bypass vulnerability classified under CWE-290, discovered in the OpenStack keystonemiddleware component, specifically within the external_oauth2_token middleware. This middleware is responsible for processing OAuth 2.0 tokens and associated identity headers that determine user roles and privileges. The vulnerability arises because the middleware fails to properly sanitize incoming authentication headers such as X-Is-Admin-Project, X-Roles, and X-User-Id before processing them. An attacker who is already authenticated (i.e., has some level of access) can exploit this flaw by crafting and sending forged HTTP headers that impersonate other users or escalate their privileges to administrative levels. This bypasses normal authentication and authorization checks, potentially granting the attacker unauthorized access to sensitive resources or administrative functions within the OpenStack environment. The affected versions include keystonemiddleware 10.5 through 10.7 before 10.7.2, 10.8 and 10.9 before 10.9.1, and 10.10 through 10.12 before 10.12.1. The vulnerability has a CVSS v3.1 base score of 9.9, reflecting its critical nature due to network exploitability, low attack complexity, required privileges but no user interaction, and a scope change that affects confidentiality and integrity substantially, with some impact on availability. No public exploits have been reported yet, but the risk remains high given the widespread use of OpenStack in cloud deployments. The vulnerability undermines the trust model of OAuth 2.0 token validation by allowing header spoofing, which can lead to full compromise of identity and access management within affected OpenStack clouds.

For European organizations, the impact of CVE-2026-22797 is significant due to the widespread adoption of OpenStack in cloud infrastructure across sectors such as finance, telecommunications, government, and critical infrastructure. Successful exploitation allows attackers to escalate privileges or impersonate users, potentially leading to unauthorized access to sensitive data, disruption of cloud services, and manipulation of cloud resources. This can result in data breaches, service outages, and loss of regulatory compliance, especially under GDPR and other data protection laws. The integrity of identity and access management systems is compromised, which can cascade into broader security failures across dependent services. Given the criticality of cloud environments in digital transformation initiatives, the vulnerability poses a direct threat to operational continuity and trust in cloud service providers. Additionally, the ability to bypass authentication controls may facilitate lateral movement within networks, increasing the risk of further exploitation and persistent threats.

European organizations should prioritize immediate patching of the keystonemiddleware component to versions 10.7.2, 10.9.1, or 10.12.1 or later, which contain fixes for this vulnerability. Until patches are applied, organizations should implement strict network segmentation and access controls to limit exposure of the OpenStack identity service to trusted networks and users only. Monitoring and logging of authentication headers should be enhanced to detect anomalous or forged header values indicative of exploitation attempts. Employing Web Application Firewalls (WAFs) or API gateways with custom rules to validate and sanitize incoming headers can provide an additional layer of defense. Conduct thorough audits of user roles and privileges to identify any unauthorized changes or suspicious activity. Organizations should also review their OAuth 2.0 token validation processes and consider additional verification mechanisms such as mutual TLS or token introspection endpoints to strengthen authentication integrity. Finally, incident response plans should be updated to include scenarios involving identity spoofing and privilege escalation within OpenStack environments.