Signal is active with 1 mentions in latest observed window
Recommended action window: Monitor and triage in normal cycle
NVD description
free5GC is an open-source implementation of the 5G core network. Prior to 1.4.5, the free5GC AUSF (Authentication Server Function) does not validate the supiOrSuci field in UE authentication requests. Null bytes (\x00) and other control characters pass through JSON parsing unchanged and are forwarded to the UDM in an unescaped URL path. This causes Go's net/url.Parse() to fail, returning HTTP 500 "System failure" and leaking internal stack traces. An unauthenticated attacker can trigger this at scale causing denial of service for all subscribers attempting authentication through the affected AUSF. This vulnerability is fixed in 1.4.5.
Priority
LOW
Exploitation
NONE
PoC
NONE
Patch
AVAILABLE
Momentum
NONE
CVE-2026-53551 free5GC is an open-source implementation of the 5G core network. Prior to 1.4.5, the free5GC AUSF (Authentication Server Function) does not validate the supiOrSuci fi… https://www.cve.org/CVERecord?id=CVE-2026-53551
Post summary
The CVE reports a validation flaw in free5GC’s AUSF before v1.4.5; the 1.4.5 update patches the issue and further details are available in the CVE record.