CVE-2026-55110
Ui Unifi Dream Machine Beast Firmware ≤ 5.1.15
Raw vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:HSummary
CVE-2026-55110 is a high-severity Permissive Cross-domain Security Policy with Untrusted Domains (CWE-942) vulnerability in Ui Unifi Dream Machine Beast Firmware. Its CVSS base score is 7.5 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Drive-by Compromise (T1189); ranked at the 5th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified map to AC-4 (Information Flow Enforcement) and SC-7 (Boundary Protection) — see the control section below for these in your framework.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-41388
Vulnerability Data
A malicious actor who lures an authenticated user to a malicious page could exploit a Cross-Origin Resource Sharing (CORS) misconfiguration found in UniFi OS to trigger actions in UniFi OS using that user's session.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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V3.4.3V3.4.6V3.5.2
Mitigating Controls (NIST 800-53 r5) AI
Information flow enforcement requires approved authorizations and would reject policies permitting untrusted domains.
Boundary protection at external interfaces stops unauthorized cross-domain communication allowed by permissive policies.
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.
Hardened configuration baselines and reviews directly prevent permissive CSP or cross-domain policies.
Secure SDLC activities include review and testing of web security policies to avoid untrusted domains.
Vulnerability identification processes can surface permissive policy misconfigurations.
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.
Security testing can detect overly permissive cross-domain policies but does not prevent their initial introduction.
Network security policies can restrict cross-domain communication but do not specifically mandate strict CSP or cross-domain policy configuration.
Security of network services includes defining allowed endpoints, which can limit untrusted domains but does not directly address web-client policy files.
Web filtering can block untrusted domains at the network level, partially mitigating permissive cross-domain policies.
Application security requirements should specify secure CSP and cross-domain policy settings, directly addressing the weakness.
Secure architecture principles include defining trust boundaries, which can reduce permissive cross-domain allowances.