CVE-2026-79665: Ech0 Authorization Bypass Vulnerability

CVE-2026-79665 Overview

CVE-2026-79665 is an authorization bypass vulnerability in Ech0 versions prior to 4.5.1. The RequireScopes middleware fails to validate scope claims when a request presents a session token. Any authenticated non-admin user can reach administrative endpoints by sending their session cookie to routes intended for privileged operators. The flaw exposes system logs, visitor statistics, user email addresses, and a live WebSocket log stream. The issue is tracked as a Missing Authorization weakness [CWE-862].

Critical Impact
Logged-in non-admin users can read admin-only data and subscribe to live log feeds without any privilege escalation exploit.

Affected Products

Ech0 versions prior to 4.5.1
Ech0 self-hosted deployments exposing authenticated endpoints
Ech0 instances using the RequireScopes middleware for admin routes

Discovery Timeline

2026-08-25 - CVE-2026-79665 published to NVD
2026-08-25 - Last updated in NVD database

Technical Details for CVE-2026-79665

Vulnerability Analysis

Ech0 protects administrative routes with a middleware named RequireScopes. The middleware is expected to check whether the caller's credential carries the scope required by the route. In vulnerable builds, this check is skipped when the credential is a session token rather than a scoped API token. The middleware treats session-authenticated requests as sufficiently authorized and passes them through to the underlying handler.

As a result, an ordinary logged-in account can invoke admin handlers directly. Attackers can retrieve system logs, visitor analytics, and stored user email addresses. They can also open the admin WebSocket endpoint and receive live log entries, which may include sensitive request data, authentication events, and other operational telemetry.

Root Cause

The root cause is missing authorization enforcement in the RequireScopes middleware for one class of credential. Scope validation is applied to scoped tokens but bypassed for session tokens. The design assumes session tokens carry full authority, without separately verifying whether the associated user holds the admin role required by the endpoint.

Attack Vector

Exploitation requires an authenticated non-admin session on the target Ech0 instance. The attacker sends HTTP requests to admin endpoints while presenting their session cookie or token. The server processes the request as if authorization succeeded. For the live log feed, the attacker upgrades the connection to WebSocket against the admin log route using the same session credential. No user interaction is required beyond the attacker's own session.

No verified proof-of-concept code is published in the referenced advisories. See the GitHub Security Advisory and the VulnCheck advisory for the vendor description.

Detection Methods for CVE-2026-79665

Indicators of Compromise

Requests to admin routes such as system log, visitor statistics, or user listing endpoints from accounts that are not members of the admin role.
WebSocket upgrade requests to admin log stream endpoints originating from non-admin session identifiers.
Unusual volumes of read requests against administrative endpoints from a single low-privilege session.

Detection Strategies

Correlate the authenticated user's role with the endpoint accessed at the reverse proxy or application log layer, and alert when non-admin users reach admin paths.
Baseline WebSocket connections to admin log endpoints and flag connections that do not originate from known admin accounts.
Review Ech0 access logs for 2xx responses on admin routes served to accounts without the admin scope.

Monitoring Recommendations

Ship Ech0 application logs and reverse proxy logs to a centralized analytics tier for role-versus-endpoint correlation.
Monitor for exfiltration-shaped patterns such as sequential enumeration of user email endpoints from a single session.
Track authentication events for sessions that suddenly access previously untouched administrative paths.

How to Mitigate CVE-2026-79665

Immediate Actions Required

Upgrade Ech0 to version 4.5.1 or later on all instances.
Invalidate active session tokens after upgrade to force re-authentication for all users.
Audit recent access logs for non-admin sessions that reached administrative endpoints and rotate any credentials exposed through the log stream.

Patch Information

The maintainers of Ech0 fixed the issue in version 4.5.1 by enforcing scope validation for session tokens in the RequireScopes middleware. Details are published in the GitHub Security Advisory GHSA-hmmq-qh6g-6wgh.

Workarounds

Restrict administrative endpoints at the reverse proxy by allow-listing source IP addresses used by administrators until the upgrade is applied.
Place Ech0 admin paths, including the WebSocket log endpoint, behind an additional authentication layer such as mTLS or an SSO forward-auth proxy.
Temporarily disable non-essential admin routes or restrict account registration to trusted users while patching is scheduled.

bash

# Example nginx snippet restricting Ech0 admin paths to an internal network
location ~ ^/(admin|api/admin|ws/admin) {
    allow 10.0.0.0/8;
    deny all;
    proxy_pass http://ech0_upstream;
}