free5GC AUSF UE Authentication Panic on Nil SuciSupiMap Interface Conversion

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-2026-33063: 0.68% estimated exploitation activity in the next 30 days; percentile 52.33 (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 Null Check vulnerability leading to Denial of Service. - Security Impact: A remote attacker can cause the AUSF service to panic and crash by sending a crafted UE authentication request that triggers a nil interface conversion in the GetSupiFromSuciSupiMap function. This results in complete denial of service for the AUSF authentication service. - Functional Impact: The GetSupiFromSuciSupiMap function attempts to perform an interface conversion from interface{} to context.SuciSupiMap without checking if the underlying value is nil. When SuciSupiMap is nil, the code panics with "interface conversion: interface {} is nil, not context.SuciSupiMap". - Affected Parties: All deployments of free5GC v4.0.1 using the AUSF UE authentication service (/nausf-auth/v1/ue-authentications endpoint). Patches Yes, the issue has been patched. The fix is implemented in PR free5gc/ausf#52 (commit: [add specific commit hash if available]). Users should upgrade to the next release…

Published by the source

18 Mar 2026, 20:06 UTC

Last modified by the source

20 Mar 2026, 21:21 UTC

Source last checked

26 Oct 2026, 15:18 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-4jrw-92fg-4jwx

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# Patch Next advisory brief: CVE-2026-33063

Advisory: free5GC AUSF UE Authentication Panic on Nil SuciSupiMap Interface Conversion
IDs: CVE-2026-33063, GHSA-4jrw-92fg-4jwx
Record: https://patchnext.com/advisories/cve-2026-33063 (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/ausf 1.4.2. A vendor fix does not mean a deployment is fixed.

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

## Suggested inspection (read-only)
- Go github.com/free5gc/ausf: 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/ausf.
- 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-4jrw-92fg-4jwx (GitHub-reviewed advisory GHSA-4jrw-92fg-4jwx lists affected ranges: Go github.com/free5gc/ausf >=0 <1.4.2)

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