CVE-2026-78330 in Syncope
Summary
by MITRE • 09/14/2026
Incorrect privilege assignment vulnerability in Apache Syncope.
When the configured JWKS settings for internal JWT authentication are disclosed (at least protocol and key), an attacker can obtain admin privileges after completing a successful authentication and obtaining a valid low-privileges JWT.
This issue affects Apache Syncope: from 3.0.0-M0 through 3.0.16, from 4.0.0-M0 through 4.0.7, from 4.1.0-M0 through 4.1.2.
Users are recommended to upgrade to version 4.0.8 / 4.1.3, which fix this issue.
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Analysis
by VulDB Data Team • 09/14/2026
The vulnerability described constitutes a critical privilege escalation flaw within Apache Syncope, specifically affecting the internal JSON Web Token authentication mechanism when configured with Java Web Key Set settings. This security defect arises from an incorrect assignment of privileges during the token generation and validation process. The core technical failure lies in how the system handles authenticated sessions that utilize low-privilege JWTs derived from disclosed JWKS configuration parameters. When an attacker successfully obtains at least the protocol details and cryptographic keys associated with these internal authentication settings, they can manipulate or forge tokens that bypass standard authorization checks. This allows a user who has completed only basic authentication to escalate their access level to administrative privileges without possessing the necessary credentials for such elevated roles.
The operational impact of this vulnerability is severe, as it compromises the integrity and confidentiality of the entire identity management system managed by Apache Syncope. Administrative accounts typically possess unrestricted access to sensitive user data, configuration settings, and security policies. By exploiting this flaw, an attacker can gain full control over the application environment. This could lead to unauthorized modification of user identities, extraction of personal identifiable information from stored directories, or complete disruption of service through malicious administrative actions. The vulnerability effectively undermines the principle of least privilege, allowing a low-privileged entity to perform high-level operations that should be strictly restricted to authorized administrators.
This issue impacts multiple versions of Apache Syncope, including releases from 3.0.0-M0 through 3.0.16 and 4.0.0-M0 through 4.0.7, as well as the 4.1.x branch up to version 4.1.2. The flaw is categorized under CWE-269, which refers to Improper Privilege Assignment, indicating that the software does not properly restrict user privileges based on their assigned roles or authentication status. From a threat modeling perspective using the MITRE ATT&CK framework, this vulnerability aligns with techniques related to Account Manipulation and potentially Token Theft if the JWKS keys are obtained through prior reconnaissance or side-channel attacks. The ability to forge valid tokens suggests weaknesses in how token signatures are verified against the disclosed public keys, allowing attackers to craft malicious JWTs that appear legitimate to the authentication middleware.
To mitigate this risk, organizations running affected versions of Apache Syncope must immediately upgrade to version 4.0.8 or 4.1.3, where these issues have been resolved. In addition to upgrading, administrators should audit their JWKS configurations to ensure that private keys are never exposed and that public key distribution is restricted to trusted internal services only. It is also advisable to implement strict network segmentation for authentication endpoints and monitor logs for unusual patterns of token generation or privilege escalation attempts. Regular security assessments and penetration testing focusing on identity management systems can help identify similar misconfigurations before they are exploited in production environments.