CVE-2026-55196

CRITICAL EPSS 43.3%
Published Jun 17, 20261w ago · Modified Jun 23, 20261w ago
9.1 CVSS 4.0
Critical
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Published Jun 17, 2026 1w ago
Last Modified Jun 23, 2026 1w ago

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.

CVSS Details

Base Score
9.1
Exploitability
—
Impact
—
Vector string
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction None
Scope X

Threat Intelligence

EPSS Exploit Probability
43.3% percentile
Exploit & Patch Status
No Known Exploit
No Patch Available

Weaknesses 1

CWE-306 Missing Authentication for Critical Function Authentication

References 5

  • github.com https://github.com/nesquena/hermes-webui/commit/4d90577e25d5537cb07290eca3fb8abff3bab316
  • github.com https://github.com/nesquena/hermes-webui/pull/4171
  • github.com https://github.com/nesquena/hermes-webui/pull/4267
  • github.com https://github.com/nesquena/hermes-webui/releases/tag/v0.51.442
  • vulncheck.com https://www.vulncheck.com/advisories/hermes-webui-unauthenticated-passkey-registration-via-authentication-bypass

Remediation

No remediation data recorded yet

Check vendor advisories and the NVD entry for patch availability.