# 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.

- **Severity:** Critical 9.3 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 9 Jul 2026
- **Updated:** 14 Jul 2026
- **Also known as:** GHSA-rfj2-6v8r-3w64

## 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 (Use of Less Trusted Source)

## 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.

## Is CVE-2026-58122 being exploited?

There is no known exploitation of CVE-2026-58122 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-58122 and fix it if it is affected.

What it is: 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.
Exploitation: There is no known exploitation of CVE-2026-58122 in the wild and no public exploit code.

Affected product: nesquena hermes-webui. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-58122/ (Markdown: https://insights.sbomify.com/CVE-2026-58122/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-58122
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-58122
- OSV: https://osv.dev/vulnerability/CVE-2026-58122

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-58122/
Summaries are generated and may contain mistakes; the official description above is the record.