{"id":"CVE-2026-55196","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-55196","generatedAt":"2026-10-28T02:11:56.548Z","title":"Hermes WebUI before 0.51.409 contains an authentication bypass vulnerability in passkey registration endpoints that allows unauthenticated remote attackers to register arbitrary passkeys.","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.","published":"2026-06-17T19:18:13.000Z","lastModified":"2026-09-17T18:16:48.000Z","status":"Deferred","sourceIdentifier":"disclosure@vulncheck.com","cvss":{"version":"4.0","score":9.1,"severity":"CRITICAL","vector":"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/M"},"cwe":["CWE-306"],"affected":[],"epss":{"score":0.00579,"percentile":0.47361,"date":"2026-10-26","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (0.58%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[],"references":[{"url":"https://github.com/nesquena/hermes-webui/commit/4d90577e25d5537cb07290eca3fb8abff3bab316","source":"disclosure@vulncheck.com"},{"url":"https://github.com/nesquena/hermes-webui/pull/4171","source":"disclosure@vulncheck.com"},{"url":"https://github.com/nesquena/hermes-webui/pull/4267","source":"disclosure@vulncheck.com"},{"url":"https://github.com/nesquena/hermes-webui/releases/tag/v0.51.442","source":"disclosure@vulncheck.com"},{"url":"https://www.vulncheck.com/advisories/hermes-webui-unauthenticated-passkey-registration-via-authentication-bypass","source":"disclosure@vulncheck.com"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-55196","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}