CVE-2026-47780

free5GC: UDR Improper ueId validation in free5GC EE subscription handlers allows arbitrary identifier persistence

Published Sep 15, 2026 CVSS 4.0 · 6.9 Medium EPSS < 1% KEV · Not listed
Description
free5GC is an open-source implementation of the 5G core network. In 4.2.3 and earlier, HandleCreateEeSubscriptions and HandleQueryeesubscriptions in free5gc/udr internal/sbi/api_datarepository.go validate the ueId path value with a regular expression whose final .+ alternative accepts every non-empty string instead of restricting identifiers to supported SUPI and GPSI formats. An actor with network reachability to the UDR SBI can submit a non-3GPP identifier to /nudr-dr/v2/subscription-data/{ueId}/context-data/ee-subscriptions, causing the identifier to pass validation and enter the normal create or query flow. The advisory does not independently establish whether authentication is required. Invalid identifiers can be persisted and retrieved as subscription records, enabling unauthorized data creation, UDR namespace pollution, persistent subscriber-metadata corruption, and interference with downstream components that trust stored identifiers to use valid 3GPP formats. The exposure is most relevant in lab, test, or loosely segmented service-based-interface deployments where direct UDR access is possible.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-6gxq-gpr8-xgjp free5GC UDR has improper `ueId` validation in EE subscription handlers that allows arbitrary identifier persistence
History
Type Values Removed Values Added
First Time appeared Free5gc
Free5gc free5gc
Vendors & Products Free5gc
Free5gc free5gc
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description free5GC is an open-source implementation of the 5G core network. In 4.2.3 and earlier, HandleCreateEeSubscriptions and HandleQueryeesubscriptions in free5gc/udr internal/sbi/api_datarepository.go validate the ueId path value with a regular expression whose final .+ alternative accepts every non-empty string instead of restricting identifiers to supported SUPI and GPSI formats. An actor with network reachability to the UDR SBI can submit a non-3GPP identifier to /nudr-dr/v2/subscription-data/{ueId}/context-data/ee-subscriptions, causing the identifier to pass validation and enter the normal create or query flow. The advisory does not independently establish whether authentication is required. Invalid identifiers can be persisted and retrieved as subscription records, enabling unauthorized data creation, UDR namespace pollution, persistent subscriber-metadata corruption, and interference with downstream components that trust stored identifiers to use valid 3GPP formats. The exposure is most relevant in lab, test, or loosely segmented service-based-interface deployments where direct UDR access is possible.
Title free5GC: UDR Improper ueId validation in free5GC EE subscription handlers allows arbitrary identifier persistence
Weaknesses CWE-20
References
Metrics cvssV4_0

{'score': 6.9, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Sep 15, 2026, 3:25 PM
Reserved
May 19, 2026, 10:36 PM
Status
Deferred
Published
Sep 15, 2026, 3:17 PM
Modified
Sep 30, 2026, 5:51 PM