CVE-2026-7588

Vulnerability

Overview

CVE-2026-7588 is a path traversal vulnerability in the coding-standards-mcp project by ggerve. The flaw resides in the get_style_guide and get_best_practices functions within server.py. These functions construct a filename by directly interpolating the user-supplied language argument into a template string (e.g., {language}_style_guide.md), which is then passed to the read_template() function. The read_template() function joins this filename with the templates/ directory using os.path.join and opens the resulting path without any validation or canonicalization [1].

Exploitation

The vulnerability can be exploited remotely without authentication. An attacker can supply a language argument containing path traversal sequences such as ../../../../tmp/secret. Because the input is not sanitized, the resulting path escapes the intended templates/ directory, allowing the server to read arbitrary files on the filesystem that match the constructed pattern (e.g., /tmp/secret_style_guide.md) [1]. The attack is straightforward and does not require any special privileges beyond network access to the MCP server.

Impact

Successful exploitation allows an attacker to read sensitive files outside the template directory. Depending on the server's file system layout, this could expose configuration files, credentials, or other confidential data. The vulnerability is classified as medium severity (CVSS 5.3) due to the requirement that the file name must match the constructed pattern, limiting the scope of files that can be read [1].

Mitigation

As of the report date (April 14, 2026), the vendor has not responded to the issue, and no fixed version has been released. The project uses rolling releases, so version details for affected and updated releases are not available [1]. Users should consider restricting network access to the MCP server, implementing input validation for the language parameter, or applying a workaround such as sanitizing the input to remove path traversal sequences until an official patch is provided.