Auth bypass in Nesquena Hermes-Webui
CVE-2026-49973
Hermes WebUI before version 0.51.358 contains an improper access control vulnerability that allows unauthenticated remote attackers to hijack initial setup by submitting the _set_password parameter to the settings API endpoint without any network origin restriction. Attackers on any reachable network can send a POST request to the settings endpoint during the first-run setup window to persist an arbitrary password hash, obtain a valid session cookie, and lock out the legitimate operator from their own instance.
Vulnerability class: Broken Authentication
EPSS: 0.005 (43.9th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 9.4 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:L.
Affected products
- Nesquena Hermes-webui — versions 0
Weakness classification (CWE)
References
- disclosure@vulncheck.com (patch)
- disclosure@vulncheck.com (issue-tracking)
- disclosure@vulncheck.com (issue-tracking)
- disclosure@vulncheck.com (release-notes)
- disclosure@vulncheck.com (third-party-advisory)
Frequently asked questions
- What is CVE-2026-49973?
- CVE-2026-49973 is a critical-severity vulnerability in Nesquena Hermes-Webui, classified under Missing Authentication for Critical Function. CVSS score: 9.4/10. Published 2026-06-11.
- How severe is CVE-2026-49973?
- Critical severity. CVSS v3 base score is 9.4 out of 10.