Hermes WebUI before 0.51.788 contains an unauthenticated remote code execution vulnerability that allows remote attackers to execute arbitrary shell commands by accessing the embedded terminal API endpoints without credentials. Attackers can create a session, attach a PTY shell, and write arbitrary commands through the terminal input endpoint to achieve full command execution as the server process user via four sequential unauthenticated HTTP requests.
https://www.vulncheck.com/advisories/hermes-webui-unauthenticated-rce-via-terminal-api
https://github.com/nesquena/hermes-webui/releases/tag/v0.51.788
https://github.com/nesquena/hermes-webui/pull/5268
https://github.com/nesquena/hermes-webui/commit/d257e5f36cfa9328600c8bde6f0de09a6ad9b6f4
Published: 2026-07-09
Updated: 2026-07-09
Base Score: 10
Vector: CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:C
Severity: Critical
Base Score: 9.8
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Severity: Critical
Base Score: 9.3
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
Severity: Critical