The vulnerability in nesquena hermes-webui arises from improper limitation of pathname to a restricted directory (CWE-22). Authenticated attackers can set or change a session workspace to any existing directory by manipulating workspace path parameters in specific API endpoints. This trust-boundary failure allows attackers to bypass intended workspace restrictions and use file read/write APIs to access or modify files outside the designated workspace, constrained only by the permissions of the hermes-webui process. The issue is present in version 0 of the product and was published on 2026-04-21. No patch or official remediation guidance is currently available.

An authenticated attacker can exploit this vulnerability to access or modify files outside the intended workspace directory, potentially leading to unauthorized data access or modification within the privileges of the hermes-webui process. This could result in data integrity and confidentiality issues depending on the files accessible to the process. There is no indication of remote code execution or privilege escalation beyond the hermes-webui process permissions. No known exploits in the wild have been reported.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is available, restrict access to the hermes-webui service to trusted users only and monitor for suspicious activity related to workspace path manipulation. Avoid exposing the service to untrusted networks. Do not rely on this vulnerability being mitigated without vendor confirmation.