CVE-2025-66719 is a critical-severity (CVSS 9.1) CWE-863 vulnerability in github.com/free5gc/nrf. A fix is available for github.com/free5gc/nrf — see the affected versions and patch details below.
Free5gc NRF is vulnerable to scope validation bypass via maliciously crafted targetNF value
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
Exploitation and automatability from CISA’s SSVC triage for CVE-2025-66719.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
github.com/free5gc/nrfReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
Description
An issue was discovered in Free5gc NRF 1.4.0. In the access-token generation logic of free5GC, the AccessTokenScopeCheck() function in file internal/sbi/processor/access_token.go bypasses all scope validation when the attacker uses a crafted targetNF value. This allows attackers to obtain an access token with any arbitrary scope.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/free5gc/nrf | all versions | 1.4.1go get github.com/free5gc/nrf@v1.4.1 |
Affected Products
nrffree5gcDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/free5gc/nrf, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update github.com/free5gc/nrf to 1.4.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-66719 is resolved across your whole dependency graph.
Workarounds
Put an independent control in front of the weakness: restrict the affected endpoint or interface to trusted networks, require an additional authentication factor or proxy-level check, and invalidate existing sessions and credentials in case the flaw has already been used.
Frequently Asked Questions
Is CVE-2025-66719 in your dependencies?
Find it across Go, including transitive dependencies.