CVE-2026-44327
Published: 27 May 2026
Summary
CVE-2026-44327 is a critical-severity Missing Authentication for Critical Function (CWE-306) vulnerability in Free5Gc Free5Gc. Its CVSS base score is 10.0 (Critical).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 11.3th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
Threat & Defense at a Glance
Threat & Defense Details
Likely Mitigating ControlsAI
Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.
Requiring identification and rationale for actions allowed without authentication ensures critical functions are not left unprotected by forcing review of authentication requirements.
Authorizing mobile device connections to organizational systems ensures authentication is performed for this critical access function.
Always invoking the reference monitor prevents missing authorization checks for protected resources.
Auditing sessions makes it possible to detect access to critical functions without required authentication.
The assessment process confirms authentication is present and effective for critical functions, preventing exploitation from missing authentication.
Certification assesses that critical functions have required authentication controls in place.
Requiring authorization servers ensures authorization is performed for protected functions.
Tailoring determines which functions require authentication and selects the appropriate baseline or compensating authentication controls.
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Missing authentication on exposed NEF SBI/OAM endpoint directly enables remote exploitation of a public-facing 5G network function (CWE-306/862).
NVD Description
free5GC is an open-source implementation of the 5G core network. Prior to 4.2.2, free5GC's NEF mounts the nnef-oam route group without inbound OAuth2/bearer-token authorization. A network attacker who can reach NEF on the SBI can hit the OAM route with…
more
no Authorization header at all and the handler returns 200 OK. The current OAM handler is a stub that returns null, but the structural defect is route-group-scoped: the entire OAM route group has no inbound auth middleware, so every future OAM operation added to this group inherits the missing auth boundary by default. This vulnerability is fixed in 4.2.2.
Deeper analysisAI
Automated synthesis unavailable for this CVE.
Details
- CWE(s)
- OWASP Top 10 Web 2025
Affected Products
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-32571
Regulatory context (EU CRA / NIS2 / DORA / UK NIS Regulations)
EU Cyber Resilience Act — coordinated disclosure
Critical and high-severity vulnerabilities in products with digital elements may trigger coordinated-disclosure obligations under the EU Cyber Resilience Act (CRA, Regulation 2024/2847). Manufacturers placing products on the EU market must notify ENISA and the relevant CSIRTs without undue delay once active exploitation is known.