CVE-2026-58123Network attack vector

Unauthenticated RCE via ungated terminal API

Published Jul 9, 2026 · Updated Jul 9, 2026

Missing authentication in Hermes WebUI before 0.51.788 allows remote attackers to execute shell commands through terminal API requests. The terminal start endpoint creates a PTY shell, and the input endpoint writes attacker-supplied data to it because check_auth() accepts every caller when authentication is disabled. A passwordless, publicly bound server is required; four unauthenticated HTTP requests execute commands with the server process account's privileges.

CVSS severity9.3
Critical
EPSS probability4.65%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Missing authentication in Hermes WebUI before 0.51.788 allows remote attackers to execute shell commands through terminal API requests. The terminal start endpoint creates a PTY shell, and the input endpoint writes attacker-supplied data to it because check_auth() accepts every caller when authentication is disabled. A passwordless, publicly bound server is required; four unauthenticated HTTP requests execute commands with the server process account's privileges.

The record

CVE
CVE-2026-58123
Published
Jul 9, 2026
Updated
Jul 9, 2026
Vendor
Nathan Esquenazi
Product
Hermes WebUI
Classifications
CWE-306, T1059, 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 <0.51.788

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Nathan Esquenazi · Hermes WebUIversion=0 <0.51.788

Published CVSS scores

9.3VulnCheckCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
9.8VulnCheckCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

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-306Missing Authentication for Critical Function
T1059Command and Scripting Interpreter
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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