Hermes WebUI prior to version 0.51.311 permits an authenticated attacker to execute arbitrary commands on the host by inserting malicious entries into the workspace repository’s .git/config file. The flaw stems from the application’s use of Git subprocess commands such as git status, git fetch, and credential helpers, which honor configuration options like core.fsmonitor, protocol.ext.allow, credential.helper, core.askPass, core.gitProxy, and environment variables such as GIT_SSH_COMMAND. This leads to a command‑execution vulnerability identified as CWE‑78.

The affected product is Hermes WebUI, provided by nesquena, for all releases earlier than 0.51.311. Any installation that allows users to add code to a workspace repository’s Git configuration is potentially vulnerable.

The CVSS score of 8.7 reflects a high severity with user interaction required and network leverage. EPSS is not available, and the vulnerability is not listed in the CISA KEV catalog, indicating that no active exploits are publicly known at this time. The attack requires a legitimate user account with write access to a workspace repository; by crafting a malicious .git/config entry the attacker can exploit Git’s subprocess handling to run arbitrary commands on the application server. Because the flaw is triggered by internal Git configuration rather than external input, the attack surface is limited to authenticated users who can modify a repository’s configuration.