CVE-2026-49446
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.
References
- https://github.com/azukaar/Cosmos-Server/commit/59c561d686c8f9843b3e092b50f6346c481d8bbf
- https://github.com/azukaar/Cosmos-Server/releases/tag/v0.22.19
- https://github.com/azukaar/Cosmos-Server/security/advisories/GHSA-2rx5-2g7j-2659
- https://github.com/azukaar/Cosmos-Server/security/advisories/GHSA-2rx5-2g7j-2659