Hermes WebUI — CVE-2026-58122 (Critical)

Date Jul 9, 2026

Type Vendor advisory

Signal Critical vendor advisory

Vendor / Product Hermes · WebUI

CVE CVE-2026-58122

Critical vendor advisory CVE-2026-58122

Summary

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.

Why it matters

This CVE carries a CRITICAL severity rating (CVSS 9.1) in Hermes WebUI. Patch or mitigate promptly.

Operator check

Review CVE-2026-58122 in your asset inventory. Apply patches per vendor guidance and verify WebUI is not exposed. CVSS score: 9.1.

Sources

NVD — CVE-2026-58122 Source reference Source reference

PatchBrief uses public sources. It does not scan environments, verify exposure, or replace vendor guidance.

Get watched-vendor alerts Subscribe free Back to feed