CVE-2026-55196
Medium
Elevated severity or exploit probability.
CVSS base
9.1
CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
EPSS — probability of exploitation (30 days)
0.8%
55.3th percentile
CISA KEV
Not listed
Weakness / dates
CWE-306
Published 2026-06-17 · modified 2026-09-17
Description
Hermes WebUI before 0.51.409 contains an authentication bypass vulnerability in passkey registration endpoints that allows unauthenticated remote attackers to register arbitrary passkeys. When HERMES_WEBUI_PASSKEY=1 is enabled with no existing credentials, POST /api/auth/passkey/register/options and POST /api/auth/passkey/register endpoints are accessible without authentication, allowing attackers to claim the first passkey and gain permanent administrative control.
References
- https://github.com/nesquena/hermes-webui/commit/4d90577e25d5537cb07290eca3fb8abff3bab316
- https://github.com/nesquena/hermes-webui/pull/4171
- https://github.com/nesquena/hermes-webui/pull/4267
- https://github.com/nesquena/hermes-webui/releases/tag/v0.51.442
- https://www.vulncheck.com/advisories/hermes-webui-unauthenticated-passkey-registration-via-authentication-bypass