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Not in CISA KEV

GHSA-4jrw-92fg-4jwx ausf

Fix: free5gc/ausf#52

GHSA-4jrw-92fg-4jwx is a NULL Pointer Dereference vulnerability in github.com/free5gc/ausf. A fix is available for github.com/free5gc/ausf — see the affected versions and patch details below.

free5GC AUSF UE Authentication Panic on Nil SuciSupiMap Interface Conversion

Also known asCVE-2026-33063GO-2026-4754
Published
Mar 18, 2026
Updated
Mar 23, 2026
Affected
1 pkg
Patched
1 / 1
Exploits
None indexed
Exploitation data as of Sep 20, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

  • CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
  • CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for GHSA-4jrw-92fg-4jwx.

EPSS Exploitation Probability

via FIRST.org ↗
0.7%probability of exploitation in next 30 days
Lower Risk0.00%
Lower risk than most CVEs50th percentile — riskier than 50% of all scored CVEsHighest risk

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Real-World Exposure

1 pkg affected
🐹github.com/free5gc/ausf

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.

Description

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.

Affected Packages

1 total 1 fixed
EcosystemPackageVulnerable rangeFix
🐹Gogithub.com/free5gc/ausfall versions1.4.2go get github.com/free5gc/ausf@v1.4.2

Detection & mitigation playbook

Open-source dependency
  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/free5gc/ausf, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

  2. Fix

    Update github.com/free5gc/ausf to 1.4.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-4jrw-92fg-4jwx is resolved across your whole dependency graph.

  3. Workarounds

    If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

  4. How O3 protects you

    O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-4jrw-92fg-4jwx can be triaged on real exposure rather than presence alone.

Tailored to GHSA-4jrw-92fg-4jwx. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

**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 `Suci
O3 Security · Impact-Aware SCA

Is GHSA-4jrw-92fg-4jwx in your dependencies?

O3 Security finds GHSA-4jrw-92fg-4jwx across Go dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.

GHSA-4jrw-92fg-4jwx: ausf DoS | O3 Security