CVE-2026-33063 free5GC AUSF UE Authentication Panic on Nil SuciSupiMap Interface Conversion

What is CVE-2026-33063?

CVE-2026-33063 is a high-severity vulnerability in Free5gc Free5gc, published on 20 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

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.

Weakness: CWE-476

Which versions are affected by CVE-2026-33063?

3 open source packages ship an affected version, including github.com/free5gc/ausf. It affects 1 product.

Products include Free5gc Free5gc.

How do I fix CVE-2026-33063?

Upgrade github.com/free5gc/ausf to 1.4.2 or later.

Is CVE-2026-33063 being exploited?

There is no known exploitation of CVE-2026-33063 in the wild and no public exploit code.

Other vulnerabilities in Free5gc Free5gc

• CVE-2026-44327 free5GC: NEF nnef-oam route group is unauthenticated; no-token requests reach the OAM handler Critical 10.0
• CVE-2026-44329 free5GC's SMF UPI management interface lacks auth middleware; unauthenticated topology read/write requests reach handlers Critical 10.0
• CVE-2026-44330 free5GC's NEF nnef-pfdmanagement API is unauthenticated; forged bearer tokens can read PFD data and create/delete PFD subscriptions Critical 10.0
• CVE-2025-63679 Memory corruption in n/a Critical 9.8
• CVE-2026-44315 free5GC's NEF 3gpp-pfd-management API is unauthenticated; forged bearer tokens can create, read, and delete PFD transactions Critical 9.4

All Free5gc Free5gc vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as GHSA-4jrw-92fg-4jwx, GO-2026-4754.