Raw vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:HSummary
CVE-2026-28798 is a critical-severity SSRF (CWE-918) vulnerability in Zimaspace Zimaos. Its CVSS base score is 9.0 (Critical).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 32th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
The strongest mitigations our analysis identified map to AC-4 (Information Flow Enforcement) and SI-10 (Information Input Validation) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
CVE-2026-28798 affects ZimaOS, a fork of CasaOS designed as an operating system for Zima devices and x86-64 systems with UEFI support. Prior to version 1.5.3, the web interface exposes a proxy endpoint at /v1/sys/proxy that can be abused to forward requests to internal localhost services. This vulnerability, classified under CWE-918 (Server-Side Request Forgery), carries a CVSS v3.1 base score of 9.0 (AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H), indicating critical severity due to its potential for high-impact network-based exploitation with changed scope.
Attackers can exploit this issue without authentication if the ZimaOS instance is reachable from the internet via a Cloudflare Tunnel configured with an externally accessible domain. By abusing the proxy endpoint, remote adversaries can make unauthorized requests to internal-only endpoints and sensitive local services on localhost, potentially leading to full compromise of confidentiality, integrity, and availability on the affected system. The high attack complexity stems from the need for specific Cloudflare Tunnel exposure.
The issue has been addressed in ZimaOS version 1.5.3, as detailed in the official release notes and security advisory. Security practitioners should upgrade to this patched version immediately. Relevant resources include the release page at https://github.com/IceWhaleTech/ZimaOS/releases/tag/1.5.3 and the GitHub advisory at https://github.com/IceWhaleTech/ZimaOS/security/advisories/GHSA-vqqj-f979-8c8m.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-18843
Vulnerability Data
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…
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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.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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V1.3.6V1.5.3V5.3.2V10.4.7
Mitigating Controls (NIST 800-53 r5) AI
Information flow enforcement can restrict which destinations the server is allowed to contact on behalf of users.
Input validation directly stops untrusted URLs from being accepted and fetched without destination checks.
Boundary protection limits the network reach of server-initiated requests even if SSRF occurs.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Secure development practices directly include input validation and destination allow-listing that prevent SSRF.
Runtime monitoring of web applications and services can detect anomalous outbound requests indicative of SSRF.
Vulnerability identification processes can discover and record SSRF flaws in web applications.
Network segmentation and egress controls can limit the damage from successful SSRF requests.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Operational threat data describing SSRF campaigns can be used to tighten outbound-request allow-lists and detection rules before attackers exploit them.