CVE-2026-33063: free5GC AUSF UE Authentication Panic on Nil SuciSupiMap Interface Conversion
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 of free5GC that includes this commit.
Workarounds There is no direct workaround at the application level. The recommendation is to apply the provided patch or restrict access to the AUSF API to trusted sources only.
Other sources
free5GC is an open source 5G core network. free5GC AUSF prior to version 1.4.2 has is an Improper Null Check vulnerability leading to Denial of Service. All deployments of free5GC v4.0.1 using the AUSF UE authentication service (/nausf-auth/v1/ue-authentications endpoint) are affected. 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. 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". free5GC AUSF version 1.4.2 patches the issue. There is no direct workaround at the application level. The recommendation is to apply the provided patch or restrict access to the AUSF API to trusted sources only.
— MITRE
Affected Software
Remediation
Patch Available
Event History
Frequently Asked Questions
What is the severity of CVE-2026-33063?
CVE-2026-33063 has a severity rating that indicates it can lead to Denial of Service by causing the AUSF service to crash.
How do I fix CVE-2026-33063?
To fix CVE-2026-33063, upgrade to free5GC AUSF version 1.4.2 or later.
What causes the CVE-2026-33063 vulnerability?
CVE-2026-33063 is caused by an improper null check in the UE authentication request processing.
Who is affected by CVE-2026-33063?
CVE-2026-33063 affects users of the free5GC AUSF versions prior to 1.4.2.
What are the implications of CVE-2026-33063?
The implications of CVE-2026-33063 include potential service outages due to the AUSF service crashing.