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CVE-2026-28798 IceWhaleTech CVE debrief

A critical vulnerability was discovered in ZimaOS, a fork of CasaOS, used in Zima devices and x86-64 systems with UEFI. The issue, tracked as CVE-2026-28798, allows an attacker to abuse a proxy endpoint exposed by ZimaOS's web interface to make requests to internal localhost services. This can lead to unauthenticated access to internal-only endpoints and sensitive local services when the product is reachable from the Internet through a Cloudflare Tunnel. The vulnerability has been patched in version 1.5.3. Administrators and users of ZimaOS should be aware of this vulnerability and take immediate action to patch their systems.

Vendor
IceWhaleTech
Product
ZimaOS
CVSS
CRITICAL 9
CISA KEV
Not listed in stored evidence
Original CVE published
2026-04-03
Original CVE updated
2026-07-24
Advisory published
2026-04-03
Advisory updated
2026-07-24

Who should care

Administrators and users of ZimaOS, especially those with the system exposed to the Internet through a Cloudflare Tunnel, should be aware of this vulnerability and take immediate action to patch their systems. This includes reviewing and restricting access to the proxy endpoint, monitoring for suspicious activity, and implementing additional security measures to protect internal services. Vulnerability management and security teams should prioritize patching and verifying the security of affected systems.

Technical summary

CVE-2026-28798 is a critical vulnerability in ZimaOS, a fork of CasaOS used in Zima devices and x86-64 systems with UEFI. An attacker can abuse a proxy endpoint (/v1/sys/proxy) exposed by ZimaOS's web interface to make requests to internal localhost services. This can lead to unauthenticated access to sensitive local services and internal-only endpoints when the product is reachable from the Internet through a Cloudflare Tunnel. The vulnerability has a CVSS score of 9 and is classified as CRITICAL. It was patched in version 1.5.3, and defenders should prioritize patching and restricting access to the proxy endpoint.

Defensive priority

High

Recommended defensive actions

  • Apply the patch by updating ZimaOS to version 1.5.3 or later.
  • Review and restrict access to the proxy endpoint (/v1/sys/proxy) to prevent external abuse.
  • Monitor for any suspicious activity related to the proxy endpoint.
  • Consider implementing additional security measures to protect internal services.
  • Review compensating controls for exposed systems while remediation is scheduled and verified.
  • Check relevant monitoring, detection, and logs for exposed assets that need extra review.
  • Track exceptions, retest remediated assets, and close the item only after evidence is documented.

Evidence notes

The vulnerability was patched in version 1.5.3 of ZimaOS. The CVE record was published on 2026-04-03T20:16:02.433Z and last modified on 2026-07-24T22:10:00.140Z. The NVD entry is currently Analyzed. Evidence is based on official CVE and NVD records, with limited additional source detail. Defenders should verify patch deployment and review proxy endpoint exposure.

Official resources

AI-assisted PatchSiren debrief based on the supplied source corpus. The CVE record was published on 2026-04-03T20:16:02.433Z and has not been modified since then. The NVD entry is currently Analyzed.