CVE-2026-11322: Hermes WebUI before 0.51.221 Path Traversal via Symlink Workspace Bypass

Synopsis

Path traversal via symlink workspace bypass in Hermes WebUI allows an authenticated attacker to escape the intended workspace boundary through the file and listing APIs. The vulnerability is reachable over the network and requires only a low-privilege account; no victim interaction is needed. Successful exploitation gives the attacker read access to arbitrary files on the host that the server process can reach, such as SSH private keys, cloud credential files, and application tokens. A patched-image rebuild at version 0.51.221 is available on HarborGuard for environments running an affected version.

HarborGuard Coverage

Exploit Conditions

• Network reachabilityRequired

  The attacker must reach the Hermes WebUI service over the network; the vulnerable file and listing APIs are exposed via the web interface.

• AuthenticationRequired

  A low-privilege account is sufficient; any valid authenticated session can supply symlinks to the workspace APIs.

• Victim interactionNot required

  The attacker exploits the API directly and does not need a user to take any action.

• Attack complexityDetail

  Exploitation is reliable and condition-free; no race conditions, memory layout dependencies, or special environmental factors are required.

Blast Radius

• Reads arbitrary files on the host that the server process has permission to open, including files outside the workspace root.
• Discloses SSH private keys stored on the host, enabling lateral movement to other systems.
• Exposes cloud provider credential files (for example, AWS credentials or GCP service account keys), allowing unauthorized API access to cloud resources.
• Leaks application tokens and configuration secrets accessible to the server process user.