free5gc UDR nudr-dr influenceData/subs-to-notify leaks SUPI in error response body without authentication

Exploitation

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

CVSS

7.5 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

EPSS

• CVE-2026-40245: 0.51% estimated exploitation activity in the next 30 days; percentile 43.28 (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 An information disclosure vulnerability in the UDR service allows any unauthenticated attacker with access to the 5G Service Based Interface (SBI) to retrieve stored subscriber identifiers (SUPI/IMSI) with a single HTTP GET request requiring no parameters or credentials. Details The endpoint GET /nudr-dr/v2/application-data/influenceData/subs-to-notify (defined in 3GPP TS 29.519) requires at least one query parameter (dnns, snssais, supis, or internalGroupIds) to filter results. In the free5GC UDR implementation, the input validation is present but ineffective because the handler does not return after sending the HTTP 400 error. The request handling flow is: 1. The function HandleApplicationDataInfluenceDataSubsToNotifyGet in ./free5gc4-2-1/free5gc/NFs/udr/internal/sbi/apidatarepository.go (around line 2793) checks whether all of dnn, snssai, internalGroupId, and supi are empty. 2. If they are all empty, it builds a problemDetails structure and calls…

Published by the source

14 Apr 2026, 20:00 UTC

Last modified by the source

16 Apr 2026, 21:57 UTC

Source last checked

26 Oct 2026, 15:19 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-wrwh-rpq4-87hf

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# Patch Next advisory brief: CVE-2026-40245

Advisory: free5gc UDR nudr-dr influenceData/subs-to-notify leaks SUPI in error response body without authentication
IDs: CVE-2026-40245, GHSA-wrwh-rpq4-87hf
Record: https://patchnext.com/advisories/cve-2026-40245 (revision 1, source checked 26 Oct 2026, 15:19 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 7.5)
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 <= 1.4.2

## 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-wrwh-rpq4-87hf (GitHub-reviewed advisory GHSA-wrwh-rpq4-87hf lists affected ranges: Go github.com/free5gc/udr >=0 <=1.4.2)

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