CVE-2026-18749 in VINCE
Summary
by MITRE • 08/12/2026
The type=track branch authorises on _is_my_case(t_attach.case) only and never checks VinceTrackAttachment.shared. A coordinator-uploaded case artefact that has NOT been marked shared is still retrievable by any case member who has (or is sent) its uuid — leaks not-yet-released coordinator material to vendors on the case.
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Analysis
by VulDB Data Team • 08/12/2026
This vulnerability represents a critical access control flaw in the case management system where the authorization mechanism fails to properly validate sharing permissions for attached files. The system implements a conditional check through the _is_my_case(t_attach.case) function that only verifies ownership of the case but completely bypasses the shared status verification that should govern access to attachments. This design flaw creates a direct pathway for unauthorized information disclosure where coordinator-uploaded artifacts can be accessed by any member of the case regardless of their role or permission level, as long as they possess the specific uuid of the attachment.
The technical implementation demonstrates a classic broken access control pattern that violates fundamental security principles. When a coordinator uploads a case artifact and fails to mark it as shared, the system should enforce strict access controls preventing vendor members from retrieving this content. However, the current implementation allows any user with the uuid to access the file because the authorization check does not incorporate the VinceTrackAttachment.shared flag into its decision-making process. This represents a CWE-285: Improper Authorization vulnerability that enables privilege escalation through improper access control validation.
The operational impact of this vulnerability extends beyond simple information leakage, creating potential security risks for sensitive coordinator-only materials. Any vendor member who receives or discovers the uuid of a non-shared attachment can retrieve and potentially disseminate confidential case information without proper authorization. This breach affects the integrity of the case management workflow where coordinators rely on sharing controls to manage information flow between different stakeholder groups. The vulnerability undermines trust in the system's access control mechanisms and creates an attack surface for malicious actors who might attempt to gather intelligence by systematically discovering and accessing non-shared attachments.
The security implications align with ATT&CK technique T1078: Valid Accounts, where attackers could leverage legitimate user accounts to access unauthorized information through improper access controls. This vulnerability also maps to CWE-352: Cross-Site Request Forgery in the context of authorization bypasses, though specifically manifests as an information disclosure rather than a request forgery scenario. Organizations implementing similar case management systems should enforce proper sharing validation at the attachment level, ensuring that access decisions consider both case ownership and explicit sharing permissions. The recommended mitigations include implementing comprehensive access control checks that validate both case membership and sharing status before granting file retrieval access, along with regular security audits to identify and remediate similar authorization bypass vulnerabilities.
This flaw demonstrates how seemingly minor implementation details in access control logic can create significant security risks. The system's failure to properly integrate the shared flag into its authorization decision tree creates a persistent vulnerability that affects all non-shared attachments regardless of case membership or role assignments. Security teams should prioritize fixing this issue by ensuring that attachment retrieval operations always validate both case ownership and sharing permissions, implementing proper access control lists, and establishing clear audit trails for attachment access events to maintain accountability and prevent unauthorized information disclosure.