CVE-2026-18991 describes a path traversal vulnerability in nanocoai NanoClaw affecting versions up to 2.0.64. The flaw resides in the send_file component of the file container/agent-runner/src/mcp-tools/core.ts, allowing an attacker to manipulate file paths remotely. This vulnerability is categorized under CWE-22 (Improper Limitation of a Pathname to a Restricted Directory). The vulnerability has a CVSS 3.1 base score of 7.3, indicating a moderate severity with network attack vector, low attack complexity, no privileges or user interaction required, and impacts on confidentiality, integrity, and availability. The vulnerability has been publicly disclosed, but no patch or vendor response is currently available.

Successful exploitation of this vulnerability allows an unauthenticated remote attacker to perform path traversal attacks, potentially accessing or manipulating files outside the intended directory. This can lead to limited confidentiality, integrity, and availability impacts as indicated by the CVSS vector. There are no known exploits in the wild at this time.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Since the project has not responded or issued a fix, users should monitor official channels for updates. Until a fix is available, consider restricting network access to the affected component or employing compensating controls to limit exposure to untrusted inputs.