CVE-2026-42081: medium-severity vulnerability in free5gc
free5GC: UE Security Capability bypass on NGAP PathSwitchRequest
Published
E-mail alert when it lands in KEV, gets a public PoC or its score goes up.
13Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 6.1epss 0.3%
free5GC is an open-source implementation of the 5G core network. Prior to 4.2.2, the AMF in Free5GC does not verify the UE Security Capabilities received in NGAP PathSwitchRequest messages against its locally stored values, as mandated by 3GPP TS 33.501 §6.7.3.1. A malicious gNB can overwrite the AMF's stored UE security capabilities with arbitrary values, which are then propagated in PathSwitchRequest Acknowledge messages and subsequent Handover Request messages. This leads to persistent handover denial-of-service for affected UEs. This vulnerability is fixed in 4.2.2.
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:L
Affected products
free5gc · free5gcRelated CVEs — free5gc
In the same product, most dangerous first.
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%