Hermes WebUI (nesquena) before version 0.51.221 contains a path‑traversal flaw that lets attackers craft symlinks pointing outside the intended workspace root. The workspace file and listing APIs resolve those symlinks without verifying that the final target stays within the protected directory, allowing read access to arbitrary host files handled by the server. Sensitive data such as SSH keys, cloud credentials or application tokens can be disclosed by exploiting this weakness.

All Hermes WebUI releases prior to v0.51.221 are vulnerable. Users running any of those versions should review their deployments for exposure of the workspace APIs and determine whether they expose this functionality to unauthenticated or low‑privileged consumers.

The CVSS score is 7.1, and the EPSS information is unavailable; the vulnerability is not present in the CISA KEV list. The flaw can be exploited by sending crafted requests to the public workspace file and listing endpoints, which processes symlinks without path enforcement. Attackers do not need elevated privileges on the host, but they must be able to supply symlinks in the workspace, indicating that the service is writable or receives user‑controlled file uploads. Once exploited, the attacker can read any host file visible to the server process.