← Vulnerability feed

Vulnerability record · CVE-2026-55196 · published 17 June 2026

CVE-2026-55196: Missing authentication for critical function vulnerability

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.

9.1 CVSS 4.0 Critical EPSS 0.82% · top 44.6% CWE-306 · Missing authentication for critical function Deferred
9.1CVSS 4.0 base score
0.82%EPSS exploitation probability, 30 days
NoNot in CISA KEV
0Affected product versions listed by NVD
5References
17 Sep 2026Last modified by NVD

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: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:

References

LinkTags
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

Track CVE-2026-55196 inside VULONE

Watch it alongside the ransomware crews, C2 infrastructure and forum chatter that reference it, query it through the API and pull it into your SIEM over TAXII.

Start free Open in platform

Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

8.8CVE-2026-67277MikroTik RouterOS btest missing authentication leaks kernel memory and crashes kernelRouterOS accepts a "related" btest connection before the primary session is authenticated, letting an unauthenticated client start an IPv4 UDP test. …KEVEPSS 1.6%analysed8.8CVE-2026-59822LiteLLM MCP endpoint auth bypass via OAuth2 passthrough fallbackLiteLLM's MCP Streamable HTTP endpoint, prior to 1.84.0, let an unauthenticated attacker send a fabricated Authorization header that triggered an OAu…KEVEPSS 0.84%analysed9.3CVE-2026-72529TrueConf Server missing authentication allows remote script executionTrueConf Server versions 5.3.X through 5.3.9, 5.4.X through 5.4.9, 5.5.X through 5.5.5, and earlier expose an undocumented function on port 4307/TCP …KEVEPSS 1.5%analysed9.8CVE-2026-46817Oracle E-Business Suite Payments missing authentication allows takeoverOracle Payments in Oracle E-Business Suite 12.2.3 through 12.2.15 contains an easily exploitable flaw in the File Transmission component. An unauthen…KEVEPSS 0.81%analysed9.8CVE-2026-56164Microsoft SharePoint Server missing authentication allows privilege elevationMicrosoft Office SharePoint Server contains a missing authentication flaw in a critical function (CWE-306), letting an unauthenticated attacker reach…KEVEPSS 1.0%analysed9.8CVE-2026-20253Splunk Enterprise PostgreSQL sidecar missing authentication allows file writesSplunk Enterprise 10.2 below 10.2.4 and 10.x below 10.0.7 expose a PostgreSQL sidecar service endpoint that lacks authentication controls. Any networ…KEVEPSS 97%analysed9.8CVE-2026-35273Oracle PeopleSoft PeopleTools missing authentication allows takeoverOracle PeopleSoft Enterprise PeopleTools (Updates Environment Management component) in versions 8.61 and 8.62 is missing authentication for a critica…KEVEPSS 9.4%analysed9.3CVE-2026-41940cPanel and WHM login flow authentication bypasscPanel, WHM and WP Squared versions after 11.40 contain a missing-authentication flaw in the login flow (CWE-306) that lets unauthenticated remote at…KEVEPSS 99%analysed

Source: NIST National Vulnerability Database (record CVE-2026-55196), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.