# CVE-2025-66719: Free5gc NRF scope validation bypass in access-token generation

Source: https://junglewise.ai/threats/cve-2025-66719-free5gc-nrf-scope-validation-bypass-in-access-token-generation  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-01-23. Updated: 2026-06-05  
License: CC BY 4.0 with a link back

CVE-2025-66719 · Severity: critical · CVSS 9.1 · Published 2026-01-23

Free5gc NRF, a core component of 5G mobile networks used for managing network functions, contains a security flaw in how it validates access requests. An attacker can bypass security checks by providing a specially crafted value, allowing them to obtain unauthorized access tokens. This could lead to unauthorized control over network services and potential exposure of sensitive mobile network data.

Technologies: [free5GC NRF](https://junglewise.ai/threats/technologies/nrf), [github.com/free5gc/nrf (Go)](https://junglewise.ai/threats/technologies/github-com-free5gc-nrf). Vendors: [free5GC](https://junglewise.ai/threats/vendors/free5gc), [Go](https://junglewise.ai/threats/vendors/go).

## Quick answers

**Is CVE-2025-66719 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2025-66719 being exploited in the wild.

**How severe is CVE-2025-66719?** Critical severity, with a CVSS score of 9.1, published 23 January 2026.

**Which products and versions are affected?** free5GC NRF 1.4.0; github.com/free5gc/nrf (Go) < 1.4.1, SEMVER:introduced=0,fixed=1.4.1.

**Is there a fix for CVE-2025-66719?** Yes. github.com/free5gc/nrf (Go): upgrade to 1.4.1 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2025-66719 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2025-66719?** Check whether you run free5GC NRF or github.com/free5gc/nrf (Go) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- github.com/free5gc/nrf (Go): upgrade to 1.4.1 or later

  ```sh
  go get github.com/free5gc/nrf@v1.4.1
  ```


## Technical details

An incorrect authorization vulnerability (CWE-863) exists in Free5gc NRF version 1.4.0. The AccessTokenScopeCheck() function within internal/sbi/processor/access_token.go fails to properly validate scopes when a maliciously crafted targetNF value is provided. A remote, unauthenticated attacker can exploit this over the network to bypass all scope validation logic. Successful exploitation allows the attacker to generate access tokens with any arbitrary scope, leading to a complete compromise of confidentiality and integrity within the affected 5G core network environment. The issue is addressed in version 1.4.1.

## Affected products

- Free5gc NRF 1.4.0

## Identifiers

- CVE-2025-66719
- GHSA-q7c8-gfjh-8v4p
- GO-2026-5570

## Timeline

- 2026-01-23: disclosed
- 2026-01-23: advisory
- 2026-06-05: patched: Advisory updated to reflect patch in 1.4.1

## References

- [https://api.github.com/users/p0sql](https://api.github.com/users/p0sql)
- [https://github.com/p0sql](https://github.com/p0sql)
- [https://api.github.com/users/p0sql/gists%7B/gist_id%7D](https://api.github.com/users/p0sql/gists%7B/gist_id%7D)
- [https://api.github.com/users/p0sql/repos](https://api.github.com/users/p0sql/repos)
- [https://avatars.githubusercontent.com/u/39105880?v=4](https://avatars.githubusercontent.com/u/39105880?v=4)
- [https://api.github.com/users/p0sql/events%7B/privacy%7D](https://api.github.com/users/p0sql/events%7B/privacy%7D)

## Related threats

- [free5GC NRF input validation bypass in NF profile registration](https://junglewise.ai/threats/cve-2026-55068-free5gc-nrf-input-validation-bypass-in-nf-profile-registration)
- [free5GC NRF type confusion in OAuth2 token endpoint](https://junglewise.ai/threats/cve-2026-44325-free5gc-nrf-type-confusion-in-oauth2-token-endpoint)
- [GO-2026-4756 - free5GC NRF Discovery EncodeGroupId Function Panics on Malformed group-id-list Parameter in github.com/free5gc/nrf](https://junglewise.ai/threats/cve-2026-33062-free5gc-nrf-discovery-encodegroupid-function-panics-on-malformed)