CVE-2026-0707 identifies a vulnerability in the Red Hat Build of Keycloak related to the handling of the Authorization header, specifically the Bearer token scheme as defined in RFC 6750. The issue stems from the authorization process occurring before the parsing and canonicalization of the header, which leads to the acceptance of malformed or non-standard inputs. The parser is overly permissive, allowing non-standard separator characters such as tabs and accepting case variations in the 'Bearer' scheme that do not conform to the RFC specification. This incorrect behavior order can be exploited by attackers to bypass authorization checks, potentially granting unauthorized access or privileges within systems relying on Keycloak for authentication and authorization. The vulnerability has a CVSS 3.1 base score of 5.3 (medium severity), reflecting that it is remotely exploitable without authentication or user interaction, impacts integrity but not confidentiality or availability, and requires low attack complexity. No known exploits have been reported in the wild as of now. The flaw highlights the importance of strict adherence to protocol specifications and proper sequencing of parsing and authorization logic in security-critical components like identity management systems.

For European organizations, this vulnerability poses a risk to the integrity of access control mechanisms managed by Keycloak. Exploitation could allow attackers to bypass authorization checks, potentially leading to unauthorized actions or privilege escalation within applications and services that rely on Keycloak for identity and access management. While confidentiality and availability are not directly impacted, the integrity compromise can facilitate further attacks or unauthorized data manipulation. Organizations in sectors with high reliance on identity federation and single sign-on solutions, such as finance, government, and critical infrastructure, may face increased risk. The medium severity rating suggests a moderate threat level; however, the ease of remote exploitation without authentication increases the urgency for mitigation. The absence of known active exploits provides a window for proactive defense. Failure to address this vulnerability could undermine trust in authentication processes and expose sensitive systems to unauthorized access.

1. Monitor Red Hat and Keycloak official channels for patches addressing CVE-2026-0707 and apply them promptly once available. 2. Implement strict input validation and normalization on the Authorization header at the application or API gateway level to reject malformed or non-standard Bearer tokens, including disallowing tabs and enforcing case sensitivity per RFC 6750. 3. Employ Web Application Firewalls (WAFs) with custom rules to detect and block suspicious Authorization header patterns that deviate from standards. 4. Conduct thorough security testing and code reviews focusing on authentication and authorization flows to ensure proper parsing and canonicalization precede authorization decisions. 5. Enhance logging and monitoring to detect anomalous authorization header usage or unexpected access patterns that could indicate exploitation attempts. 6. Educate developers and security teams about the importance of correct header parsing order and adherence to protocol specifications. 7. Consider deploying compensating controls such as multi-factor authentication and strict session management to reduce impact if authorization bypass occurs.