CVE-2026-19331 in obsidian-mcp-server
Summary
by MITRE • 08/09/2026
A vulnerability was identified in bazylhorsey obsidian-mcp-server 1.0.0. This affects the function readCanvas/writeCanvas of the file src/services/CanvasService.ts. Such manipulation leads to path traversal. An attack has to be approached locally. The project was informed of the problem early through an issue report but has not responded yet.
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Analysis
by VulDB Data Team • 08/09/2026
The vulnerability in bazylhorsey obsidian-mcp-server version 1.0.0 represents a critical path traversal flaw within the CanvasService.ts file that exposes the application to unauthorized file system access. This vulnerability specifically impacts the readCanvas and writeCanvas functions which handle canvas data operations, creating an opportunity for local attackers to manipulate file paths and gain access to sensitive system resources beyond the intended application boundaries.
The technical implementation of this vulnerability stems from insufficient input validation and sanitization within the canvas service functions. When these functions process user-supplied canvas identifiers or file paths, they fail to properly validate or sanitize the input parameters before using them in file system operations. This allows malicious actors to craft path traversal sequences that can navigate beyond the intended directory structure, potentially accessing configuration files, system binaries, or other sensitive data stored on the local filesystem.
From an operational impact perspective, this vulnerability creates significant security risks for systems running the affected obsidian-mcp-server version. Since the attack vector requires local access, it primarily affects scenarios where attackers already have shell access or are operating within the same system environment as the vulnerable service. However, the implications remain severe as attackers could potentially escalate privileges, extract sensitive configuration data, modify application behavior, or even establish persistent backdoors through manipulation of canvas files that are processed by the service.
The vulnerability aligns with CWE-22 Path Traversal and follows patterns commonly associated with directory traversal attacks in web applications and server-side services. This weakness enables attackers to bypass normal access controls and potentially access files outside of the intended directories, representing a fundamental breakdown in the application's security boundaries. The issue also maps to ATT&CK technique T1059 Command and Scripting Interpreter where local command execution could be facilitated through path traversal attacks.
Mitigation strategies should focus on implementing comprehensive input validation and sanitization for all file path operations within the CanvasService.ts functions. Developers must ensure that all user-supplied inputs are properly validated against a whitelist of allowed characters and patterns, with strict enforcement of directory boundaries during file system operations. Additionally, the service should operate with minimal required privileges, implement proper access controls, and employ secure coding practices including the use of safe file path construction methods and absolute path resolution to prevent manipulation of relative paths.
The lack of response from the project maintainers following the initial issue report represents a concerning gap in vulnerability management practices that could leave users exposed to potential exploitation. Organizations using this software should implement immediate compensating controls including network segmentation, privilege restrictions, and monitoring for unusual file access patterns while awaiting official patches or updates from the project maintainers. Regular security audits and threat modeling exercises should also be conducted to identify similar vulnerabilities in other components of the application stack.
The vulnerability demonstrates the importance of proper input validation in server-side applications, particularly those handling user data through file system operations. Without adequate protection mechanisms, even seemingly benign functions can become attack vectors that compromise entire systems. This case highlights the need for comprehensive security testing including static code analysis, dynamic application security testing, and regular vulnerability assessments to identify and remediate such issues before they can be exploited in production environments.