Vulnerability in Nesquena Hermes-Webui
CVE-2026-58122
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 9.1 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N.
EPSS exploit prediction
EPSS: 0.004 (29.1th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 29th percentile — 29.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000
Affected products
- Nesquena Hermes-Webui — versions 0
Weakness classification (CWE)
References
- github.com/nesquena/hermes-webui/releases/tag/v0.51.307 (release-notes)
- github.com/nesquena/hermes-webui/pull/3758 (issue-tracking)
- github.com/nesquena/hermes-webui/commit/70596e6993be0d4cee083c1c1a86f5e7ad5d57b7 (patch)
- www.vulncheck.com/advisories/hermes-webui-authentication-bypass-via-x-forwarded… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-58122?
- CVE-2026-58122 is a critical-severity vulnerability in Nesquena Hermes-Webui, classified under CWE-348. CVSS score: 9.1/10. Published 2026-07-09.
- How severe is CVE-2026-58122?
- Critical severity. CVSS v3 base score is 9.1 out of 10.