CVE-2026-0707 identifies a vulnerability in the Red Hat Build of Keycloak's Authorization header parser, specifically in how it processes the Bearer authentication scheme defined by RFC 6750. The parser is overly permissive, accepting non-standard characters such as tabs as separators and tolerating case variations that deviate from the RFC specification. This incorrect behavior order—performing authorization before proper parsing and canonicalization—can lead to scenarios where malformed or non-standard Authorization headers bypass intended access controls. Since the parser accepts these irregular inputs, an attacker could craft Authorization headers that circumvent security checks, potentially gaining unauthorized access or performing actions beyond their privileges. The vulnerability is network exploitable without requiring authentication or user interaction, increasing its risk profile. However, the impact is limited to integrity, as confidentiality and availability are not affected. The CVSS score of 5.3 (medium severity) reflects this moderate risk. No known exploits have been reported, and no patches have been linked at the time of publication. Organizations relying on Red Hat Keycloak for authentication and authorization should be aware of this flaw and prepare to implement mitigations once patches are available.

For European organizations, this vulnerability poses a risk primarily to the integrity of access control mechanisms within applications using Red Hat Build of Keycloak for identity and access management. Unauthorized users might exploit the permissive parsing to bypass authorization checks, potentially leading to privilege escalation or unauthorized actions within protected systems. While confidentiality and availability remain unaffected, the integrity compromise can result in unauthorized data modifications or administrative actions. This risk is particularly relevant for sectors with stringent access control requirements such as finance, healthcare, and government services. The lack of required authentication or user interaction for exploitation increases the attack surface, especially for externally facing services. Organizations with automated or federated identity systems relying on Keycloak are at higher risk. The absence of known exploits provides a window for proactive mitigation, but vigilance is necessary given the potential for future exploitation.

1. Monitor Red Hat and Keycloak security advisories closely for official patches addressing CVE-2026-0707 and apply them promptly once available. 2. Implement strict input validation and sanitization on Authorization headers at the application or API gateway level to reject non-standard characters and enforce RFC 6750 compliance. 3. Employ Web Application Firewalls (WAFs) with custom rules to detect and block malformed Authorization headers containing tabs or unusual case variations. 4. Conduct thorough code reviews and penetration testing focusing on authentication and authorization flows to identify similar parsing weaknesses. 5. Where feasible, enforce multi-factor authentication (MFA) to add an additional layer of security beyond bearer tokens. 6. Log and monitor authentication attempts for anomalies that may indicate exploitation attempts involving malformed headers. 7. Consider deploying runtime application self-protection (RASP) solutions that can detect and block suspicious authorization header manipulations in real time. 8. Educate developers and security teams about the importance of strict adherence to protocol specifications in authentication mechanisms.