CVE-2026-33064

moderate-risk

Published 2026-03-20

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.

Do I need to act?

0.20% chance of exploitation

EPSS score — low exploit probability

Not on CISA KEV list

No confirmed active exploitation reported to CISA

Patch status unknown

Check vendor advisories for fix availability and mitigation guidance

CVSS 7.5/10 High

NETWORK / LOW complexity

Affected Products (1)

Udm

Affected Vendors

Free5Gc

References (4)

Exploit https://github.com/free5gc/free5gc/issues/781

Patch https://github.com/free5gc/free5gc/security/advisories/GHSA-7g27-v5wj-jr75

Patch https://github.com/free5gc/udm/commit/65d7070f4bfd016864cbbaefbd506bbc85d2fa92

Issue Tracking https://github.com/free5gc/udm/pull/78

/ 100

moderate-risk

Severity 26/34 · High

Exploitability 1/34 · Minimal

Exposure 5/34 · Minimal