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
Published · last modified .
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.
EPSS exploit prediction
EPSS: 0.046 (91.5th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 91st percentile — 91.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.013 · newest: 0.046 · change: +0.033
Affected products
- Nesquena Hermes-Webui — versions 0
Weakness classification (CWE)
References
- github.com/nesquena/hermes-webui/releases/tag/v0.51.788 (release-notes)
- github.com/nesquena/hermes-webui/pull/5268 (issue-tracking)
- github.com/nesquena/hermes-webui/commit/d257e5f36cfa9328600c8bde6f0de09a6ad9b6f4 (patch)
- www.vulncheck.com/advisories/hermes-webui-unauthenticated-rce-via-terminal-api (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.