NULL pointer dereference in Free5gc
CVE-2026-33064
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.008 (54.1th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 54th percentile — 54.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.005 · newest: 0.008 · change: +0.003
Affected products
- Free5gc — versions < 1.4.2
- Free5gc Udm
Weakness classification (CWE)
References
- github.com/free5gc/free5gc/security/advisories/GHSA-7g27-v5wj-jr75 (Patch, Vendor Advisory)
- github.com/free5gc/free5gc/issues/781 (Exploit, Patch, Issue Tracking, Vendor Advisory)
- github.com/free5gc/udm/pull/78 (Patch, Issue Tracking)
- github.com/free5gc/udm/commit/65d7070f4bfd016864cbbaefbd506bbc85d2fa92 (Patch)
Frequently asked questions
- What is CVE-2026-33064?
- CVE-2026-33064 is a high-severity vulnerability in Free5gc, classified under CWE-478. CVSS score: 7.5/10. Published 2026-03-20.
- How severe is CVE-2026-33064?
- High severity. CVSS v3 base score is 7.5 out of 10.