CVE-2026-68481 in CXF
Summary
by MITRE • 08/06/2026
In Apache CXF's DefaultEncryptingOAuthDataProvider, revoked access tokens still decrypt successfully, and TokenIntrospectionService reports active:true. The same applies to refresh tokens. This violates the RFC stipulations that 'The authorization server MUST invalidate the token.' and 'introspection of a revoked token MUST return {"active":false}'. Users are recommended to upgrade to versions 4.2.3 or 4.1.8 or 3.6.12, which fix this issue.
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Analysis
by VulDB Data Team • 08/06/2026
The vulnerability in Apache CXF's DefaultEncryptingOAuthDataProvider represents a critical security flaw that undermines the fundamental principles of OAuth token management and validation. This issue affects the token introspection service implementation where revoked access tokens and refresh tokens continue to decrypt successfully despite being invalidated by the authorization server. The core problem manifests when the TokenIntrospectionService returns active:true for tokens that have been explicitly revoked, directly violating established OAuth security protocols and creating a significant vector for unauthorized access exploitation.
The technical flaw stems from improper token state management within the DefaultEncryptingOAuthDataProvider component where the system fails to maintain accurate tracking of revoked token statuses. This implementation error allows the decryption process to succeed on tokens that should no longer be valid, effectively bypassing the authorization server's token invalidation mechanisms. The service continues to report these revoked tokens as active in introspection responses, creating a false sense of security for applications relying on proper token validation. This behavior directly contravenes RFC 7009 requirements for token introspection services and violates the principle that authorization servers must invalidate tokens upon revocation to prevent further unauthorized use.
The operational impact of this vulnerability extends beyond simple access control failures to encompass potential data breaches and privilege escalation scenarios. Attackers can exploit this weakness by leveraging revoked tokens to gain continued access to protected resources, effectively rendering token invalidation mechanisms useless. The implications are particularly severe for applications that depend on proper OAuth token lifecycle management, as they may incorrectly assume valid token status when operating with revoked credentials. This vulnerability creates persistent security gaps where unauthorized parties can maintain access to sensitive systems and data even after legitimate revocation procedures have been executed.
Organizations using affected Apache CXF versions face substantial risk exposure due to this validation failure that compromises the integrity of their OAuth implementations. The vulnerability affects multiple major versions including 4.2.3, 4.1.8, and 3.6.12, indicating a widespread issue within the software's token management infrastructure. Security teams must urgently assess their environments for affected installations and implement immediate mitigations through version upgrades as recommended by Apache CXF security advisories. The fix addresses fundamental flaws in how token states are tracked and validated, ensuring that revoked tokens properly fail decryption attempts and return accurate active status indicators to maintain proper OAuth security boundaries.
This vulnerability aligns with CWE-284 access control weaknesses and maps to ATT&CK technique T1566 for credential access through token manipulation. The flaw demonstrates poor input validation and insufficient state management in authentication components, creating a persistent backdoor that can be exploited across multiple system interfaces. Organizations should implement comprehensive monitoring for unauthorized access attempts and conduct thorough security audits of their OAuth implementations to identify potential exploitation vectors. The recommended upgrades not only address this specific vulnerability but also improve overall token lifecycle management and enhance the robustness of authorization server implementations against similar credential validation attacks.