CVE-2026-31863 in anytype-heart
Summary
by MITRE • 03/11/2026
Anytype Heart is the middleware library for Anytype. The challenge-based authentication for the local gRPC client API can be bypassed, allowing an attacker to gain access without the 4-digit code. This vulnerability is fixed in anytype-heart 0.48.4, anytype-cli 0.1.11, and Anytype Desktop 0.54.5.
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Analysis
by VulDB Data Team • 03/20/2026
The vulnerability identified as CVE-2026-31863 affects Anytype Heart, which serves as a critical middleware library for the Anytype ecosystem. This middleware component facilitates communication between various Anytype applications and provides essential functionality for local gRPC client API operations. The issue stems from a flawed authentication mechanism that undermines the security model designed to protect local system access through challenge-based authentication. The vulnerability specifically targets the authentication flow for local gRPC client APIs, where a 4-digit code is intended to serve as a protective barrier against unauthorized access. This authentication mechanism represents a fundamental security control that should prevent unauthorized users from interacting with local system resources through the Anytype platform.
The technical flaw in this vulnerability manifests as an authentication bypass that allows attackers to circumvent the challenge-based authentication process entirely. The 4-digit code verification mechanism, which should act as a second factor of authentication, becomes ineffective due to implementation weaknesses in the Anytype Heart library. This flaw likely involves improper validation of authentication tokens or insufficient session management that permits unauthorized access to the local gRPC API endpoints. The vulnerability represents a critical security weakness in the authentication architecture, potentially allowing attackers to execute arbitrary commands or access sensitive local system resources without proper authorization. According to CWE classification, this vulnerability aligns with CWE-287, which addresses improper authentication issues, and may also relate to CWE-305, concerning authentication bypass through multiple means.
The operational impact of this vulnerability extends beyond simple unauthorized access, potentially enabling attackers to manipulate local system data, execute malicious operations, or gain persistence within the Anytype environment. Since this affects the middleware library that supports multiple Anytype applications including desktop clients, the attack surface becomes significantly broader than initially apparent. An attacker who successfully exploits this vulnerability could potentially access local files, modify system configurations, or perform actions that compromise the integrity and confidentiality of user data stored within the Anytype ecosystem. The local gRPC API access provides privileged operations that could be leveraged for more sophisticated attacks including privilege escalation or lateral movement within the local network environment. This vulnerability directly impacts the principle of least privilege and could allow attackers to perform operations that should be restricted to authorized users only.
The fix for this vulnerability has been implemented in specific versions of the affected software components, including anytype-heart 0.48.4, anytype-cli 0.1.11, and Anytype Desktop 0.54.5. These updates address the authentication bypass by strengthening the challenge-based authentication mechanism and ensuring proper validation of 4-digit codes before granting access to local gRPC API endpoints. The remediation likely involves implementing proper session management, strengthening token validation procedures, and ensuring that authentication challenges are properly enforced throughout the middleware layer. Organizations using Anytype should immediately update to these patched versions to eliminate the risk of exploitation. The vulnerability also demonstrates the importance of proper authentication implementation in middleware components and serves as a reminder of the critical security implications when authentication mechanisms are improperly designed or implemented. From an ATT&CK perspective, this vulnerability relates to T1078.004, which covers valid accounts with weak passwords or authentication bypass techniques, and T1566, concerning credential harvesting through various attack vectors that can exploit authentication weaknesses in software components.