Is this vulnerability remotely exploitable?

It can be, depending on deployment. If an attacker can send access-token requests to the NRF over the SBI or through any exposed management interface, they may remotely exploit the flaw without needing local system access.

What level of access does an attacker need to exploit this issue?

The attacker must be able to influence or construct token issuance requests to the NRF and control values like `targetNF`. This might involve compromising a network function, abusing misconfigured service access, or exploiting weak controls around who can call the NRF's token endpoint.

What is the safest general fix pattern?

The safest pattern is to make scope determination solely dependent on verified NF identity and centrally defined authorization policies, and to ensure that all execution paths within `AccessTokenScopeCheck()` and related logic enforce those policies without exceptions. Any invalid or unexpected input, including unusual `targetNF` values, should cause the request to be denied rather than issued with unchecked scopes.

Severity:

CRITICAL RISK

(9.1)

Improper Authorization Scope Validation (CWE-863) in free5GC NRF Access Token Generation

CVE-2025-66719

Published:

Jan 23, 2026

Status:

Analyzed

Summary

Affected Context

Exploit Preconditions

Why This Happens

Potential Impact

General Mitigation Guidance

How Teams Detect Issues Like This

Frequently Asked Questions

Source

NDV

Recent Vulnerabilities

CWE-306

CRITICAL RISK

CRITICAL

(9.8)

Missing Authentication for Forgot-Password Email Change API (CWE-306)

Account Takeover / Loss of Account Control

February 17, 2026

CWE-77;CWE-78

HIGH RISK

HIGH

(7.3)

OS Command Injection (CWE-78) in node-sonos-http-api TTS Provider for macOS

Remote Code Execution on the Server Host

February 17, 2026

Vulnerability Type

Category:

Improper Authorization

CWE:

CWE-863

Impact:

Privilege Escalation and Unauthorized Access via Forged Access Token Scopes

Severity:

CRITICAL RISK

(9.1)

CVSS Version:

3.1

Vulnerability Type

Category:

Improper Authorization

CWE:

CWE-863

Impact:

Privilege Escalation and Unauthorized Access via Forged Access Token Scopes

Severity:

CRITICAL RISK

(9.1)

CVSS Version:

3.1

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355 Bryant St. San Francisco, CA 94107, USA

Ask AI for summary of CodeAnt

Improper Authorization Scope Validation (CWE-863) in free5GC NRF Access Token Generation

Summary

Affected Context

Exploit Preconditions

Why This Happens

Potential Impact

General Mitigation Guidance

How Teams Detect Issues Like This

Frequently Asked Questions

Source

Recent Vulnerabilities

CRITICAL RISK

CRITICAL

(9.8)

Missing Authentication for Forgot-Password Email Change API (CWE-306)

HIGH RISK

HIGH

(7.3)

OS Command Injection (CWE-78) in node-sonos-http-api TTS Provider for macOS

Vulnerability Type

Vulnerability Type

Vulnerability Type

Vulnerability Type

Catch This CVE While Code Is Being Written

Ship clean & secure code faster

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