free5GC UDM incorrectly returns 500 for empty supi path parameter in PATCH sdm-subscriptions reques

Exploitation

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

CVSS 4.0

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

EPSS

• CVE-2026-33192: 0.33% estimated exploitation activity in the next 30 days; percentile 25.77 (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.

Impact This is an Improper Error Handling vulnerability with Information Exposure implications, combined with an HTTP Method Translation issue. - Security Impact: The UDM incorrectly converts a downstream 400 Bad Request (from UDR) into a 500 Internal Server Error when handling PATCH requests with an empty supi path parameter. Additionally, the UDM incorrectly translates the PATCH method to PUT when forwarding to UDR, indicating a deeper architectural issue. This leaks internal error handling behavior and makes it difficult for clients to distinguish between client-side errors and server-side failures. - Functional Impact: When a client sends a PATCH request with an empty supi (e.g., double slashes // in URL path), the UDM forwards a PUT request to UDR with the malformed path, which correctly returns 400. However, UDM propagates this as 500 SYSTEMFAILURE instead of returning the appropriate 400 error to the client. This violates REST API best practices for PATCH operations and may…

Published by the source

18 Mar 2026, 20:11 UTC

Last modified by the source

20 Mar 2026, 21:24 UTC

Source last checked

26 Oct 2026, 15:18 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-5rvc-5cwx-g5x8

Preview the exact text before you copy it. Commands are read-only suggestions; review them before running anything.

# Patch Next advisory brief: CVE-2026-33192

Advisory: free5GC UDM incorrectly returns 500 for empty supi path parameter in PATCH sdm-subscriptions reques
IDs: CVE-2026-33192, GHSA-5rvc-5cwx-g5x8
Record: https://patchnext.com/advisories/cve-2026-33192 (revision 1, source checked 26 Oct 2026, 15:18 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 8.7)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: github.com/free5gc/udm 1.4.2. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/free5gc/udm: affected < 1.4.2; fixed in 1.4.2

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

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on github.com/free5gc/udm.
- 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-5rvc-5cwx-g5x8 (GitHub-reviewed advisory GHSA-5rvc-5cwx-g5x8 lists affected ranges: Go github.com/free5gc/udm >=0 <1.4.2)

Commands are suggestions: review each one before running it.