CVE-2026-58122 Hermes WebUI < 0.51.307 Authentication Bypass via X-Forwarded-For Header Spoofing
Attackers can bypass authentication via spoofed headers to access internal services, modify configurations, and steal access tokens in Hermes WebUI.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-58122?
CVE-2026-58122 is a critical authentication bypass vulnerability in nesquena hermes-webui, published on 9 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
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.
Weakness: CWE-348
Which versions are affected by CVE-2026-58122?
How do I fix CVE-2026-58122?
No fix has been published for CVE-2026-58122 yet. Limit exposure of the affected software until one is available.
Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.
Is CVE-2026-58122 being exploited?
There is no known exploitation of CVE-2026-58122 in the wild and no public exploit code.
Sources
Also known as GHSA-rfj2-6v8r-3w64.