CVE-2026-44325
free5GC NRF: type-confusion panic in POST /oauth2/token structured-form parser via Reflect.Set on incompatible types
Impact
free5GC is an open-source implementation of the 5G core network. Prior to 4.2.2, free5GC's NRF root SBI endpoint POST /oauth2/token contains a parser-level type-confusion bug family. The handler in NFs/nrf/internal/sbi/api_accesstoken.go reflects over models.NrfAccessTokenAccessTokenReq, special-cases only plain string and NrfNfManagementNfType fields, and treats every other field as if it were a single models.PlmnId. The parsed *models.PlmnId is then assigned with reflect.Value.Set() to whichever field name the attacker put in the form body, which panics whenever the destination field's real type is incompatible (slice, different struct, primitive). Gin recovery converts each panic into HTTP 500, but the endpoint remains remotely panicable from a single unauthenticated form-encoded request and is repeatedly triggerable. This vulnerability is fixed in 4.2.2.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| go | github.com/free5gc/nrf | < 1.4.3 | 1.4.3 |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Free5gc | Free5gc | before 4.2.2 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/advisories/GHSA-f8qv-7x5w-qr48
- https://github.com/free5gc/free5gc/security/advisories/GHSA-f8qv-7x5w-qr48
- https://github.com/free5gc/free5gc/issues/918
- https://github.com/free5gc/nrf/pull/83
- https://github.com/free5gc/nrf/commit/f7bc77daa7425506af7569f2e61c2a210f5a0423
- https://nvd.nist.gov/vuln/detail/CVE-2026-44325