Access Token Scope Bypass in Free5gc Network Functions by Free5gc
CVE-2025-66719

9.1CRITICAL

Key Information:

Vendor

Free5gc

Status
Free5gc NRF
Vendor
CVE Published:
23 January 2026

What is CVE-2025-66719?

A vulnerability in Free5gc NRF version 1.4.0 could allow an attacker to bypass access token scope validation. The issue occurs in the access-token generation logic, specifically in the AccessTokenScopeCheck() function, which fails to validate the requested scope when an attacker uses a specially crafted targetNF value. This could enable unauthorized users to obtain access tokens for various unrestricted scopes, significantly compromising the integrity and security of the network functions.

References

https://github.com/free5gc/free5gc/issues/736
https://github.com/free5gc/nrf/pull/73

CVSS V3.1

Score:
9.1
Severity:
CRITICAL
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.