CVE-2026-75843 in ArcadeDB
Summary
by MITRE • 08/18/2026
ArcadeDB before 26.8.1 fails to bind the authenticated principal on the gRPC transaction executor thread in beginTransaction, allowing authenticated readers to execute JavaScript commands without scripting authorization checks. Attackers can execute executeCommand with a transaction ID to run unrestricted JavaScript that creates server-wide administrator accounts.
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Analysis
by VulDB Data Team • 08/18/2026
The vulnerability identified in ArcadeDB versions prior to 26.8.1 represents a critical authentication bypass and privilege escalation flaw within the gRPC interface, specifically affecting the transaction management subsystem. The core technical issue stems from an improper binding of the authenticated principal context during the initialization phase of database transactions. When a client initiates a new transaction via the beginTransaction method on the gRPC executor thread, the system fails to correctly associate or propagate the security credentials and identity information established during the initial authentication handshake. This architectural oversight results in the execution environment operating under an unauthenticated or default context state rather than maintaining the verified user session that was originally authenticated by the client.
This failure in principal binding directly impacts the authorization logic for scripting commands, which are typically subject to strict access controls due to their potential for arbitrary code execution on the server side. In a properly secured implementation, any attempt to execute JavaScript through the database interface would trigger an intermediate security check verifying that the current user possesses specific scripting permissions or administrative privileges. However, because the principal is not bound correctly in this context, these authorization checks are effectively bypassed. The system treats the request as if it originates from a user with unrestricted access, allowing authenticated users who lack explicit scripting rights to invoke dangerous JavaScript functions without triggering any denial of service or permission errors.
The operational impact of this vulnerability is severe, particularly for deployments where external clients connect via gRPC and possess standard read-only or limited write permissions. An attacker can leverage the executeCommand API endpoint by supplying a valid transaction ID obtained through normal authenticated interactions to inject and run arbitrary JavaScript code on the database server. Since there are no scripting authorization checks in place during this specific execution path, the injected scripts operate with full administrative privileges inherent to the database process itself. This capability allows for complete compromise of the underlying system integrity, as demonstrated by the ability to create new administrator accounts that possess unrestricted access to all data and configuration settings within the ArcadeDB instance.
From a classification perspective, this vulnerability aligns closely with CWE-287, which describes Improper Authentication, specifically regarding the failure to maintain identity context across different execution phases or threads. It also relates to CWE-926, indicating improper export of security-critical information through interfaces that do not enforce consistent access controls. In terms of offensive tactics, this flaw facilitates techniques associated with MITRE ATT&CK T1078, Valid Accounts, as it allows an attacker to leverage legitimate but low-privileged credentials to achieve high-level administrative actions typically reserved for system administrators. The ability to execute arbitrary code via scripting interfaces further maps to T1620, Reflective Code Injection, or more broadly to command execution capabilities that compromise the host environment.
Mitigation strategies must prioritize immediate software updates and architectural review of security context propagation in multi-threaded environments. Users running ArcadeDB versions earlier than 26.8.1 should upgrade to the patched version immediately to resolve the principal binding issue within the gRPC transaction executor. For organizations unable to patch instantly, network-level controls such as restricting direct access to the gRPC port and enforcing strict firewall rules can limit exposure. Additionally, implementing a Web Application Firewall or API gateway with deep packet inspection capabilities may help detect and block anomalous JavaScript execution attempts that deviate from expected behavioral patterns of authenticated users. Long-term remediation should involve auditing all database interfaces for similar context propagation failures to ensure that security contexts are consistently maintained across all entry points and transaction lifecycles.