CVE-2026-52466 in VuFind
Summary
by MITRE • 08/06/2026
Open Library Foundation VuFind v11.0.3 and v4.1 is vulnerable to toInorrect Access Control. The application fails to stop processing an incoming request in VuFind\Controller\AbstractBase::validateAccessPermission after it has found that controller level access permissions do not allow access to the requested function. The requester receives a response indicating that access was denied, but the actual function is executed regardless of that.
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Analysis
by VulDB Data Team • 08/06/2026
The vulnerability in Open Library Foundation VuFind versions 4.1 and 11.0.3 represents a critical incorrect access control flaw that undermines the application's security model. This issue manifests in the AbstractBase::validateAccessPermission method where the system properly identifies unauthorized access attempts but fails to properly terminate request processing. The flaw creates a scenario where access denial is communicated to the requester through a response message, yet the underlying function execution continues regardless of the permission validation outcome. This represents a classic bypass vulnerability where the authorization check occurs but does not effectively enforce the access restriction, allowing malicious actors to potentially execute unauthorized operations while receiving misleading feedback about their access status.
The technical implementation of this vulnerability stems from flawed control flow logic within the access validation mechanism. When VuFind processes incoming requests, it validates controller-level permissions through AbstractBase::validateAccessPermission, but the method's design allows execution to continue past the permission check point. This creates an execution path where the application acknowledges denial but proceeds with function execution, effectively rendering the access control mechanism ineffective. The flaw operates at the application logic level rather than at network or authentication layers, making it particularly dangerous as it can be exploited by users who have legitimate access to the system but lack proper authorization for specific functions.
This incorrect access control vulnerability directly impacts the application's integrity and confidentiality by allowing unauthorized execution of privileged operations. Attackers could potentially exploit this flaw to perform actions they should not be permitted to execute, including accessing restricted data, modifying system configurations, or executing administrative functions. The operational impact extends beyond simple unauthorized access as it undermines the trust model that users place in the application's security controls, potentially leading to data breaches, privilege escalation, and system compromise. The vulnerability affects both major version lines, indicating a fundamental architectural issue that has persisted across different releases.
The security implications of this vulnerability align with CWE-285, which addresses improper authorization scenarios in software systems. This classification specifically covers situations where access control mechanisms fail to properly enforce restrictions, allowing unauthorized operations to proceed despite explicit denial. From an ATT&CK framework perspective, this vulnerability maps to privilege escalation techniques and defense evasion strategies as attackers can leverage the flawed access control to bypass intended security boundaries without triggering obvious detection mechanisms. The vulnerability's persistence across multiple versions also suggests inadequate security testing during development cycles and insufficient input validation in the access control implementation.
Mitigation strategies should focus on immediate code-level fixes that ensure proper request termination upon access denial. The AbstractBase::validateAccessPermission method must be modified to completely halt execution flow when permission checks fail, rather than simply returning a denial response while continuing processing. Organizations should implement comprehensive access control testing procedures including penetration testing and security code reviews to identify similar logic flaws in other parts of the application. Additionally, deploying web application firewalls and implementing proper logging of access control events can help detect exploitation attempts and provide forensic evidence for incident response activities. Regular security updates and version management practices should be enforced to ensure all instances remain protected against known vulnerabilities.