CVE-2026-33064
Fix: free5gc/udm@65d7070CVE-2026-33064 is a CWE-478 vulnerability in github.com/free5gc/udm. O3 Security confirms whether CVE-2026-33064 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
free5GC UDM DataChangeNotification Procedure Panic Due to Nil Pointer Dereference
Real-World Exposure
github.com/free5gc/udmReal-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
Free5GC is an open-source Linux Foundation project for 5th generation (5G) mobile core networks. Versions prior to 1.4.2 are vulnerable to procedure panic caused by Nil Pointer Dereference in the /sdm-subscriptions endpoint. A remote attacker can cause the UDM service to panic and crash by sending a crafted POST request to the /sdm-subscriptions endpoint with a malformed URL path containing path traversal sequences (../) and a large JSON payload. The DataChangeNotificationProcedure function in notifier.go attempts to access a nil pointer without proper validation, causing a complete service crash with "runtime error: invalid memory address or nil pointer dereference". Exploitation would result in UDM functionality disruption until recovery by restart. This issue has been fixed in version 1.4.2.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/free5gc/udm | all versions | 1.4.2 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/free5gc/udm. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update github.com/free5gc/udm to 1.4.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-33064 is resolved across your whole dependency graph.
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.
How O3 protects you
O3 pinpoints whether CVE-2026-33064 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2026-33064. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-33064 in your dependencies?
O3 detects CVE-2026-33064 across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.