CVE-2026-113874 in HAPI FHIR
Summary
by MITRE • 10/23/2026
SmileCDR HAPI FHIR allows an untrusted bundle body to replace a partition identity previously established by a trusted source, and does not enforce storage partition entitlement by default. An attacker authorized for one tenant can read from or write to another tenant's partition.
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Analysis
by VulDB Data Team • 10/23/2026
The vulnerability in SmileCDR, which is built upon the HAPI FHIR framework, represents a critical failure in multi-tenant isolation mechanisms within healthcare data management systems. This flaw allows an untrusted bundle body to overwrite or replace a partition identity that was previously established by a trusted source. In typical operations, the system relies on initial authentication and authorization steps to assign specific partitions to users based on their tenant context. However, due to this defect, subsequent requests containing maliciously crafted bundles can manipulate these internal identifiers, effectively hijacking the session's contextual boundaries. This behavior indicates that the application does not strictly validate whether the partition identity provided in a request matches the one assigned during the initial trusted handshake or authentication phase.
From a technical perspective, this issue stems from insufficient validation of input data regarding tenant context and storage partitions. The system fails to enforce strict binding between the authenticated user's permissions and the specific resource partition they are attempting to access. By allowing an untrusted source to redefine the partition identity, the application bypasses its own security controls that are designed to segregate data among different tenants or organizations. This lack of enforcement means that the integrity of the session context is compromised early in the request processing pipeline, leading to a state where subsequent actions are executed under false pretenses regarding which tenant's data should be accessed.
The operational impact of this vulnerability is severe, as it directly compromises confidentiality and potentially integrity within multi-tenant environments. An attacker who has been authorized for access to one specific tenant can exploit this flaw to read from or write to another tenant's partition. In the context of healthcare applications using FHIR standards, this could lead to unauthorized exposure of protected health information (PHI), violating regulations such as HIPAA in the United States or GDPR in Europe. Furthermore, if an attacker gains write access, they could inject fraudulent medical records or alter existing data for a different tenant, leading to significant legal and reputational damage for both the service provider and the affected organizations.
This vulnerability aligns with CWE-284, which describes Improper Access Control, specifically where security restrictions are not enforced correctly during resource access. It also maps closely to MITRE ATT&CK technique T1078, Valid Accounts, as it involves an attacker leveraging legitimate credentials for one entity to gain unauthorized access to resources belonging to another entity through manipulation of system context rather than credential theft. The failure to enforce storage partition entitlement by default exacerbates the risk, suggesting that even with standard configurations, systems may remain vulnerable unless additional hardening measures are applied manually.
To mitigate this issue, developers and administrators must ensure that SmileCDR is updated to the latest version where these validation checks have been implemented. It is crucial to verify that all incoming bundle bodies undergo strict validation against established session contexts before any partition identity is accepted or processed. Implementing defense-in-depth strategies such as rigorous input sanitization and explicit enforcement of tenant isolation at every layer of the application stack can prevent similar exploits. Additionally, organizations should conduct regular security audits focused on multi-tenant architecture integrity to ensure that no unintended data leakage paths exist between isolated partitions.