Free5gc: Security Vulnerabilities
free5GC UDR is the user data repository (UDR) for free5GC, an an open-source project for 5th generation (5G) mobile core networks. In versions up to and including 1.4.1, the NEF component reliably leaks internal parsing error details (e.g., invalid character 'n' after top-level value) to remote clients, which can aid attackers in service fingerprinting. All deployments of free5GC using the Nnef_PfdManagement service may be affected. free5gc/udr pull request 56 contains a patch for the issue. There is no direct workaround at the application level. The recommendation is to apply the provided patch.
CVSS Score
6.6
EPSS Score
0.0
Published
2026-02-24
free5GC SMF provides Session Management Function for free5GC, an open-source project for 5th generation (5G) mobile core networks. In versions up to and including 1.4.1, SMF panics due to nil pointer dereference and the SMF process terminates. This is triggered by a malformed PFCP SessionReportRequest on the SMF PFCP (UDP/8805) interface. No known upstream fix is available, but some workarounds are available. ACL/firewall the PFCP interface so only trusted UPF IPs can reach SMF (reduce spoofing/abuse surface); drop/inspect malformed PFCP SessionReportRequest messages at the network edge where feasible, and/or add recover() around PFCP handler dispatch to avoid whole-process termination (mitigation only).
CVSS Score
6.6
EPSS Score
0.001
Published
2026-02-24
free5GC is an open-source project for 5th generation (5G) mobile core networks. Versions up to and including 1.4.1 of the User Data Repository are affected by Improper Error Handling with Information Exposure. The NEF component reliably leaks internal parsing error details (e.g., invalid character 'n' after top-level value) to remote clients, which can aid attackers in service fingerprinting. All deployments of free5GC using the Nnef_PfdManagement service may be vulnerable. free5gc/udr pull request 56 contains a patch. No direct workaround is available at the application level. Applying the official patch is recommended.
CVSS Score
6.6
EPSS Score
0.001
Published
2026-02-24
free5gc UDM provides Unified Data Management (UDM) for free5GC, an open-source project for 5th generation (5G) mobile core networks. In versions up to and including 1.4.1, the service reliably leaks detailed internal error messages (e.g., strconv.ParseInt parsing errors) to remote clients when processing invalid pduSessionId inputs. This exposes implementation details and can be used for service fingerprinting. All deployments of free5GC using the UDM Nudm_UECM DELETE service may be vulnerable. free5gc/udm pull request 76 contains a fix for the issue. No direct workaround is available at the application level. Applying the official patch is recommended.
CVSS Score
6.6
EPSS Score
0.001
Published
2026-02-24
free5gc UDM provides Unified Data Management (UDM) for free5GC, an open-source project for 5th generation (5G) mobile core networks. In versions up to and including 1.4.1, remote attackers can inject control characters (e.g., %00) into the ueId parameter, triggering internal URL parsing errors (net/url: invalid control character). This exposes system implementation details and can aid in service fingerprinting. All deployments of free5GC using the UDM Nudm_UECM service may be affected. free5gc/udm pull request 76 contains a fix for the issue. No direct workaround is available at the application level. Applying the official patch is recommended.
CVSS Score
6.6
EPSS Score
0.0
Published
2026-02-24
free5gc UDM provides Unified Data Management (UDM) for free5GC, an open-source project for 5th generation (5G) mobile core networks. Versions up to and including 1.4.1 have a NULL Pointer Dereference vulnerability. Remote unauthenticated attackers can trigger a service panic (Denial of Service) by sending a crafted PUT request with an unexpected ueId, crashing the UDM service. All deployments of free5GC using the UDM component may be affected. free5gc/udm pull request 76 contains a fix for the issue. No direct workaround is available at the application level. Applying the official patch is recommended.
CVSS Score
6.6
EPSS Score
0.005
Published
2026-02-24
free5GC go-upf is the User Plane Function (UPF) implementation for 5G networks that is part of the free5GC project. Versions prior to 1.2.8 have a Heap-based Buffer Overflow (CWE-122) vulnerability leading to Denial of Service. Remote attackers can crash the UPF network element by sending a specially crafted PFCP Session Modification Request with an invalid SDF Filter length field. This causes a heap buffer overflow, resulting in complete service disruption for all connected UEs and potential cascading failures affecting the SMF. All deployments of free5GC using the UPF component may be affected. Version 1.2.8 of go-upf contains a fix.
CVSS Score
2.7
EPSS Score
0.002
Published
2026-02-23
free5GC is an open-source project for 5th generation (5G) mobile core networks. Versions up to and including 1.4.1 of free5GC's AMF service have a Buffer Overflow vulnerability leading to Denial of Service. Remote unauthenticated attackers can crash the AMF service by sending a specially crafted NAS Registration Request with a malformed 5GS Mobile Identity, causing complete denial of service for the 5G core network. All deployments of free5GC using the AMF component may be affected. Pull request 43 of the free5gc/nas repo contains a fix. No direct workaround is available at the application level. Applying the official patch is recommended.
CVSS Score
6.6
EPSS Score
0.005
Published
2026-02-23
free5GC UDR is the user data repository (UDR) for free5GC, an an open-source project for 5th generation (5G) mobile core networks. Versions prior to 1.4.1 contain an Improper Error Handling vulnerability with Information Exposure. All deployments of free5GC using the Nnef_PfdManagement service may be affected. The NEF component reliably leaks internal parsing errors (e.g., invalid character 'n' after top-level value) to remote clients. This can aid attackers in fingerprinting server software and logic flows. Version 1.4.1 fixes the issue. There is no direct workaround at the application level. The recommended mitigation is to apply the provided patch.
CVSS Score
2.7
EPSS Score
0.0
Published
2026-02-23
free5GC is an open-source project for 5th generation (5G) mobile core networks. free5GC go-upf versions up to and including 1.2.6, corresponding to free5gc smf up to and including 1.4.0, have an Improper Input Validation and Protocol Compliance vulnerability leading to Denial of Service. Remote attackers can disrupt core network functionality by sending a malformed PFCP Association Setup Request. The UPF incorrectly accepts it, entering an inconsistent state that causes subsequent legitimate requests to trigger SMF reconnection loops and service degradation. All deployments of free5GC using the UPF and SMF components may be affected. As of time of publication, a fix is in development but not yet available. No direct workaround is available at the application level. Applying the official patch, once released, is recommended.
CVSS Score
2.7
EPSS Score
0.003
Published
2026-02-23