CVE-2026-28798: Zimaspace Zimaos

Critical severity, CVSS 10.0. EPSS: 0.5% chance of exploitation in the next 30 days.

ZimaOS is a fork of CasaOS, an operating system for Zima devices and x86-64 systems with UEFI. Prior to version 1.5.3, a proxy endpoint (/v1/sys/proxy) exposed by ZimaOS's web interface can be abused (via an externally reachable domain using a Cloudflare Tunnel) to make requests to internal localhost services. This results in unauthenticated access to internal-only endpoints and sensitive local services when the product is reachable from the Internet through a Cloudflare Tunnel. This issue has been patched in version 1.5.3.

Affected products

• Zimaspace Zimaos: before 1.5.3 (fixed in 1.5.3)

Published 2026-04-03. Last modified 2026-07-24.