CVE-2026-58122Network attack vector

Authentication bypass via spoofed forwarded IP header

Published Jul 9, 2026 · Updated Jul 9, 2026

Authentication bypass in Nathan Esquenazi Hermes WebUI before 0.51.307 allows remote attackers to access local-only onboarding endpoints. The onboarding IP checks trust the leftmost X-Forwarded-For value as the client address, so a loopback value satisfies the local-origin gate. Unauthenticated access enables SSRF to internal services, configuration and API-key overwrites, or OAuth device-code flows that store persistent tokens.

CVSS severity9.3
Critical
EPSS probability0.37%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authentication bypass in Nathan Esquenazi Hermes WebUI before 0.51.307 allows remote attackers to access local-only onboarding endpoints. The onboarding IP checks trust the leftmost X-Forwarded-For value as the client address, so a loopback value satisfies the local-origin gate. Unauthenticated access enables SSRF to internal services, configuration and API-key overwrites, or OAuth device-code flows that store persistent tokens.

The record

CVE
CVE-2026-58122
Published
Jul 9, 2026
Updated
Jul 9, 2026
Vendor
Nathan Esquenazi
Product
Hermes WebUI
Classifications
CWE-348, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 9, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 9, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <0.51.307

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Nathan Esquenazi · Hermes WebUIversion=0 <0.51.307

Published CVSS scores

9.3VulnCheckCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
9.1VulnCheckCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-348Use of Less Trusted Source
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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