free5GC UDR has improper ueId validation in EE subscription handlers that allows arbitrary identifier persistence

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS 4.0

4.9 · CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:L/SA:N/E:U · score source

EPSS

• CVE-2026-47780: 0.54% estimated exploitation activity in the next 30 days; percentile 45.37 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary The free5GC UDR accepts arbitrary non-3GPP ueId values in the EE subscription creation and query flows because the regular expression used for validation ends with the catch-all alternative |.+. This causes the validation logic to accept any non-empty string rather than restricting input to expected SUPI/GPSI-style formats. In a tested deployment, a crafted value such as ARBITRARYSTRING was successfully stored through the POST /nudr-dr/v2/subscription-data/{ueId}/context-data/ee-subscriptions endpoint and later retrieved through the corresponding GET endpoint, demonstrating persistent database pollution and broken trust boundaries in the UDR data model. An improper input validation issue exists in the free5GC UDR EE subscription handlers responsible for creating and querying UE event exposure subscriptions. The affected code validates ueId with a regular expression that includes a final |.+ branch, which matches any non-empty string and defeats the intended 3GPP identifier…

Published by the source

11 Jun 2026, 13:25 UTC

Last modified by the source

11 Jun 2026, 13:25 UTC

Source last checked

26 Oct 2026, 15:23 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-6gxq-gpr8-xgjp

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# Patch Next advisory brief: CVE-2026-47780

Advisory: free5GC UDR has improper `ueId` validation in EE subscription handlers that allows arbitrary identifier persistence
IDs: CVE-2026-47780, GHSA-6gxq-gpr8-xgjp
Record: https://patchnext.com/advisories/cve-2026-47780 (revision 1, source checked 26 Oct 2026, 15:23 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 4.9)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor response not established. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/free5gc/udr: affected <= 1.4.3

## Suggested inspection (read-only)
- Go github.com/free5gc/udr: check the installed version with your package manager.

## Supported action
No complete vendor fix is recorded. Follow the primary source's mitigation guidance and check this record again before closing anything.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on github.com/free5gc/udr.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-6gxq-gpr8-xgjp (GitHub-reviewed advisory GHSA-6gxq-gpr8-xgjp lists affected ranges: Go github.com/free5gc/udr >=0 <=1.4.3)

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