Threat Intelligence Database

CVE-2026-86540 is a critical arbitrary code execution vulnerability in the Knowns Language Server Protocol (LSP) detection and startup pipeline. It arises because the project-level configuration file (.knowns/config.json) allows an attacker to specify an arbitrary binary path in the 'settings.lsp.languages.<lang>.binary' field without validation. This untrusted binary is executed twice per session: once during a health check and again when the LSP server starts. When combined with a separate config overwrite vulnerability, this flaw enables unauthenticated remote code execution.

A path traversal vulnerability exists in knowns through version 0.33.0 due to improper validation of the path query parameter in the workspace browse endpoint. This flaw allows remote attackers to enumerate arbitrary directories on the host filesystem by traversing the directory structure. The vulnerability can be used to locate project directories and potentially identify targets for further exploitation.

knowns through 0.33.0 exempts the project.set action from permission guard checks unconditionally, allowing read-only agent sessions to bypass restrictions. Attackers can invoke project.set to repoint the server at another project directory and obtain write access capabilities.

knowns versions up to 0.33.0 contain a path traversal vulnerability in the code.find MCP tool that allows AI agent sessions to read arbitrary files on the host system outside the intended project directory. This occurs because the path argument is not properly confined to the project root, enabling attackers to supply absolute or relative traversal paths to access sensitive files.

knowns versions up to 0.33.0 have a path traversal vulnerability in the template engine that allows attackers to read and write files outside the project root. This can lead to overwriting critical files, stealing credentials, or persistent code execution. The vulnerability is rated high severity with a CVSS score of 8.6.

knowns versions before 0.31.0 contain a vulnerability in the /api/opencode proxy endpoint where the x-opencode-directory request header is not properly validated. This allows remote attackers to specify arbitrary directory paths, potentially enabling file operations outside the intended project root on the host system. The vulnerability has a critical severity with a CVSS 4.0 score of 9.3.

knowns versions before 0.30.0 contain an authorization bypass vulnerability where mutating code actions are incorrectly classified as read-only operations. Attackers with read-restricted sessions can exploit code.replace to modify permission configurations and escalate privileges on subsequent calls.

knowns versions before 0.30.0 serve the management API without authentication on all network interfaces by default, with no password required on fresh installations. Attackers can access the unauthenticated /api/tunnel/start endpoint to provision a public tunnel and republish the API at a publicly accessible address.

knowns before 0.30.0 fails to validate import names in the import routes, allowing unauthenticated attackers to write files outside the imports directory. Attackers can supply traversal sequences in the name parameter to escape the imports directory and overwrite arbitrary files writable by the server process.

knowns versions before 0.30.0 contain a path traversal vulnerability in the handleCodeReplace() function that allows attackers to overwrite arbitrary files outside the project root. Attackers can supply absolute paths or relative paths containing directory traversal sequences to write malicious content to sensitive files like shell startup scripts or SSH configuration files.