What is CVE-2026-58123?

CVE-2026-58123 is a critical-severity vulnerability in Nesquena Hermes-Webui, classified under Missing Authentication for Critical Function. CVSS score: 9.8/10. Published 2026-07-09.

How severe is CVE-2026-58123?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Auth bypass in Nesquena Hermes-Webui

CVE-2026-58123

Hermes WebUI before 0.51.788 contains an unauthenticated remote code execution vulnerability that allows remote attackers to execute arbitrary shell commands by accessing the embedded terminal API endpoints without credentials. Attackers can create a session, attach a PTY shell, and write arbitrary commands through the terminal input endpoint to achieve full command execution as the server process user via four sequential unauthenticated HTTP requests.

Vulnerability class: Broken Authentication

EPSS: 0.009 (57.3th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

Affected products

Nesquena Hermes-webui — versions 0

Weakness classification (CWE)

CWE-306 — Missing Authentication for Critical Function

References

disclosure@vulncheck.com (release-notes)
disclosure@vulncheck.com (issue-tracking)
disclosure@vulncheck.com (patch)
disclosure@vulncheck.com (third-party-advisory)

Frequently asked questions

What is CVE-2026-58123?: CVE-2026-58123 is a critical-severity vulnerability in Nesquena Hermes-Webui, classified under Missing Authentication for Critical Function. CVSS score: 9.8/10. Published 2026-07-09.
How severe is CVE-2026-58123?: Critical severity. CVSS v3 base score is 9.8 out of 10.