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ZimaosOperating system · Zimaspace

CVE-2026-28798

CRITICAL · 10.0 CVSS v3.1 Published 2026-04-03
Fix available
A fix is available. Upgrade to 1.5.3 or later.
See remediation →
100/100
Remediation priority · Urgent
Public exploit Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
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.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

ZimaOS versions before 1.5.3 contain an SSRF vulnerability in the `/v1/sys/proxy` web API endpoint. When the system is exposed externally via a Cloudflare Tunnel, unauthenticated attackers can abuse this proxy to make arbitrary requests to internal localhost services, bypassing network segmentation and accessing sensitive internal endpoints.

MitigationUpgrade to ZimaOS version 1.5.3 or later to patch the vulnerable proxy endpoint. If immediate upgrade is not possible, ensure the web interface is not externally accessible via Cloudflare Tunnel or implement additional authentication/filtering on the proxy endpoint.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
ZimaosOperating system
Affected:< 1.5.3

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Changed
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Check installed ZimaOS version
    Access the ZimaOS admin interface or system settings to view the current firmware/software version. Compare this against the affected range: versions before 1.5.3.
    Affected if Installed version is 1.5.2 or earlier (any version < 1.5.3)
  2. Verify /v1/sys/proxy endpoint exists
    Locate the API endpoint configuration or documentation for ZimaOS. Check if the /v1/sys/proxy endpoint is present in the system routing configuration.
    Affected if The /v1/sys/proxy endpoint exists and is enabled in the ZimaOS installation
  3. Determine if web interface is externally exposed via Cloudflare Tunnel
    Review Cloudflare Tunnel configuration settings. Check if a tunnel is configured to route external HTTP/HTTPS traffic to the ZimaOS web interface.
    Affected if A Cloudflare Tunnel is configured and actively exposing the ZimaOS web interface to the public internet
  4. Confirm proxy functionality is accessible without authentication
    If possible, test a local request to the /v1/sys/proxy endpoint. Verify whether the endpoint accepts requests without requiring authentication credentials.
    Affected if The /v1/sys/proxy endpoint accepts requests without authentication

You are affected if ZimaOS version is less than 1.5.3 AND the web interface is exposed externally via Cloudflare Tunnel, allowing unauthenticated access to the vulnerable proxy endpoint.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 1.5.3 or later
Fixed in 1.5.3
Interim mitigation

Upgrade to ZimaOS version 1.5.3 or later to patch the vulnerable proxy endpoint. If immediate upgrade is not possible, ensure the web interface is not externally accessible via Cloudflare Tunnel or implement additional authentication/filtering on the proxy endpoint.

Recommended fix Moderate confidence

1.5.3

  1. Upgrade ZimaOS to version 1.5.3 or later to obtain the patch for the SSRF vulnerability
  2. If using Cloudflare Tunnel to expose ZimaOS externally, ensure the upgrade is applied before restarting the tunnel
  3. After upgrading, verify that the /v1/sys/proxy endpoint either requires authentication or is properly restricted
  4. Review access controls to ensure internal-only services are not exposed to unauthenticated external requests

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Zimaos Scoped from the published advisory
  • Consultation3.0 h
  • Implementation2.0 h
  • Testing3.0 h
  • Review / QA2.0 h
10.0 hours of engineering $1,770
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-28798 in production — separate from our analysis above.

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What this is

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What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
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