CVE-2026-55784: fallo de gravedad alta en free5gc
free5GC AUSF authentication contexts can be overwritten by concurrent requests for the same SUPI
Publicada el · Actualizada el
Aviso por correo cuando entre en el KEV, tenga PoC pública o suba de nota.
21Vexday Risk Score
Sin señal de explotación. Ningún artefacto público de explotación conocido hasta ahora.
ssvc Trackcvss 7.5epss 0.4%
free5GC is an open-source implementation of the 5G core network. In version 1.4.4 and earlier, the AUSF component stores per-subscriber authentication state in a global sync.Map named AUSFContext.UePool in internal/context/context.go, keyed only by SUPI. Every request handled by internal/sbi/processor/ue_authentication.go creates an AusfUeContext, and AddAusfUeContextToPool executes ausfContext.UePool.Store(ausfUeContext.Supi, ausfUeContext), unconditionally replacing the active context for that SUPI. An attacker with access to the AUSF SBI/N12 interface can send concurrent POST /nausf-auth/v1/ue-authentications requests for the same target SUPI, causing all attempts to share one logical authentication context URL while K_aut, XRES, and EapID are repeatedly overwritten. A valid EAP-AKA' response for an earlier challenge is then checked against the latest context, causing AT_MAC verification to fail and denying authentication to the selected subscriber while the request flood continues. No fixed version is available as of this review.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Productos afectados
free5gc · free5gcCVEs relacionadas — free5gc
En el mismo producto, de las más peligrosas a las menos.
CVE-2026-53551MEDIUMfree5GC AUSF: null byte injection in supiOrSuci causes HTTP 500 internal service failureEPSS 0.7%CVE-2026-55068CRITICALfree5GC: NRF nnrf-nfm lacks NF Profile input validation — enables NF Registration Poisoning with arbitrary service endpointsEPSS 0.6%CVE-2026-47780MEDIUMfree5GC: UDR Improper ueId validation in free5GC EE subscription handlers allows arbitrary identifier persistenceEPSS 0.5%CVE-2026-40245HIGHFree5GC: UDR nudr-dr influenceData/subs-to-notify leaks SUPI in error response body without authenticationEPSS 0.5%CVE-2026-33064HIGHfree5GC UDM DataChangeNotification Procedure Panic Due to Nil Pointer DereferenceEPSS 0.5%CVE-2026-40247HIGHfree5gc UDR improper path validation allows unauthenticated access to Traffic Influence SubscriptionsEPSS 0.5%