Vulnerability in Hermes WebUI (CVE-2026-55196)
Summary
Vulnerability in Hermes WebUI (CVE-2026-55196). Confidential information can be exposed externally. Exploitable via POST /api/auth/passkey/register/options.
Original description
The description as published by the source.
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.
Source: GitHub Security Advisories (Global) NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-55196 has been found in Hermes WebUI.
Attackers can target a specific entry point like POST /api/auth/passkey/register/options over the network to misuse the product.
Confidential information can be exposed externally. CVSS score: 9.1/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Hermes WebUI CVE-2026-55196" on the vendor's site.
CVE-2026-55196 (Hermes WebUI) — CWE-306 / CVSS v3 9.1
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: POST /api/auth/passkey/register/options / POST /api/auth/passkey/register
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (CWE-306) exists in Hermes WebUI. Attackers reach the vulnerable code path via POST /api/auth/passkey/register/options without authentication.
Check the vendor advisory for the affected versions of Hermes WebUI. Attack surface: POST /api/auth/passkey/register/options / POST /api/auth/passkey/register.
Severity: Critical (CVSS 9.1/10). Confidential information can be exposed externally.
Update to the patched release per vendor advisory.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual POST /api/auth/passkey/register/options requests with malformed payloads or SQL meta-characters. Audit SBOM/dependencies to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
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1Identify exposure identify
Audit SBOM/dependencies for affected components.資産台帳・SBOM・依存マニフェストで Hermes WebUI を使っているサービスとバージョンを洗い出す。
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2Hunt for indicators of compromise detect
grep 'POST /api/auth/passkey/register/options' /var/log/nginx/access.log | grep -E '(unusual_payload|sqli_pattern)'アクセスログで
POST /api/auth/passkey/register/optionsへの異常なリクエスト (不正な認証ヘッダ・SQLメタ文字)を過去 30〜90日分捜索。WAF/SIEM があれば該当パスのアラート発火履歴を確認。 -
3Post-deployment verification verify
Replay attack against POST /api/auth/passkey/register/options on staging to confirm patch closes the vectorパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番では Step 2 と同じログクエリでアラート再発が無いか継続監視。