What is CVE-2026-33063?

CVE-2026-33063 is a high-severity null pointer dereference vulnerability in github.com/free5gc/ausf (go), affecting versions < 1.4.2. It is fixed in 1.4.2. The application dereferences a null pointer, causing a crash.

Which versions of github.com/free5gc/ausf are affected by CVE-2026-33063?

github.com/free5gc/ausf (go) versions < 1.4.2 is affected.

Is there a fix for CVE-2026-33063?

Yes. CVE-2026-33063 is fixed in 1.4.2. Upgrade to this version or later.

Is CVE-2026-33063 exploitable, and should I be worried?

Whether CVE-2026-33063 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk.

What actually determines whether CVE-2026-33063 is exploitable, and how bad it is?

Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.

CVE-2026-33063 in github.com/free5gc/ausf

Q: Which versions of github.com/free5gc/ausf are affected by CVE-2026-33063?

github.com/free5gc/ausf (go) versions < 1.4.2 is affected.

Q: Is there a fix for CVE-2026-33063?

Yes. CVE-2026-33063 is fixed in 1.4.2. Upgrade to this version or later.

Q: Is CVE-2026-33063 exploitable, and should I be worried?

Whether CVE-2026-33063 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk.

Q: What actually determines whether CVE-2026-33063 is exploitable, and how bad it is?

Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.

Q: How do I fix CVE-2026-33063?

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

Summary

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.

Impact

The application dereferences a null pointer, causing a crash. Typical impact: denial of service via crash.

Affected versions

github.com/free5gc/ausf (< 1.4.2)

Security releases

github.com/free5gc/ausf → 1.4.2 (go)

Kodem intelligence

Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.

Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.

Already deployed Kodem?

See it in your environment New to Kodem? Get a demo →

Remediation advice

Upgrade github.com/free5gc/ausf to 1.4.2 or later to resolve this vulnerability.

Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.

Frequently Asked Questions

What is CVE-2026-33063? CVE-2026-33063 is a high-severity null pointer dereference vulnerability in github.com/free5gc/ausf (go), affecting versions < 1.4.2. It is fixed in 1.4.2. The application dereferences a null pointer, causing a crash.
Which versions of github.com/free5gc/ausf are affected by CVE-2026-33063? github.com/free5gc/ausf (go) versions < 1.4.2 is affected.
Is there a fix for CVE-2026-33063? Yes. CVE-2026-33063 is fixed in 1.4.2. Upgrade to this version or later.
Is CVE-2026-33063 exploitable, and should I be worried? Whether CVE-2026-33063 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
What actually determines whether CVE-2026-33063 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
How do I fix CVE-2026-33063? Upgrade github.com/free5gc/ausf to 1.4.2 or later.