CVE-2026-58122: Nesquena Hermes-Webui

Critical severity, CVSS 9.1. EPSS: 0.4% chance of exploitation in the next 30 days.

Hermes WebUI before 0.51.307 contains an authentication bypass vulnerability that allows unauthenticated remote attackers to circumvent local-origin IP restrictions on onboarding endpoints by supplying a spoofed X-Forwarded-For header with a loopback address. Attackers can exploit this bypass to perform server-side request forgery against internal services including cloud metadata endpoints, overwrite LLM provider configuration and API keys with attacker-controlled values, or initiate OAuth device-code flows to obtain persistent access tokens stored in auth.json.

Affected products

• Nesquena Hermes-Webui: before 0.51.307 (fixed in 0.51.307)

Published 2026-07-09. Last modified 2026-07-14.