CVE-2026-49446: azukaar cosmos-server Improper Authorization

Vulnerability summary

CVE-2026-49446 is a medium (CVSS 6.1) Improper Authorization vulnerability in azukaar cosmos-server. EPSS estimates a 0.30% chance of exploitation in the next 30 days, higher than 21.3% of scored vulnerabilities.

Timeline

1. 15-09-2026
   PublishedVulnerability first disclosed.
2. 15-09-2026
   Last modifiedVulnerability information updated.

Description

Cosmos provides users the ability self-host a home server by acting as a secure gateway to your application, as well as a server manager. Prior to 0.22.19, tokenMiddleware in src/proxy/routerGen.go can return through the Constellation tunnel bypass before removing x-cosmos-user, x-cosmos-role, x-cosmos-user-role, and x-cosmos-mfa headers and before invoking AdminOnlyWithRedirect. An attacker with a valid x-cstln-auth API key for an enrolled device who reaches Cosmos through the Constellation Nebula tunnel can supply a chosen x-cosmos-user value to a route with AuthEnabled enabled when the upstream application trusts that forward-auth header. The request can bypass Cosmos JWT, password, MFA, and AdminOnly checks, allowing user impersonation and admin-tier reads or writes exposed by the proxied application. This issue is fixed in version 0.22.19.

• CWE-285Improper AuthorizationThe product does not perform or incorrectly performs an authorization check when an actor attempts to access a resource or perform an action.
• CWE-290Authentication Bypass by SpoofingThis attack-focused weakness is caused by incorrectly implemented authentication schemes that are subject to spoofing attacks.