CVE-2026-33064
highpriority · track · 30EPSS 0.005 · 42 %ileEUUSEPSS · scored 2026-10-27
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.
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 6.6–8.7
ssvc
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weaknesses
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affected products (3)
Products and version ranges known to be affected.
advisories (2)
Vendor and ecosystem advisories describing this.
- GHSA-7g27-v5wj-jr75free5GC UDM DataChangeNotification Procedure Panic Due to Nil Pointer Dereference2026-03-18ghsa · osvUS
**Impact** This is a NULL Pointer Dereference vulnerability leading to Denial of Service. - **Security Impact**: 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". - **Functional Impact**: The service crashes completely, requiring manual restart. All UDM functionality is disrupted until recovery. - **Affected Parties**: All deployments of free5GC v4.0.1 using the UDM HTTP callback functionality. **Patches** Yes, the issue has been patched. The fix is implemented in PR free5gc/udm#78. 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 implement API gateway-level filtering to block requests containing path traversal sequences.
- GO-2026-4757free5GC UDM DataChangeNotification Procedure Panic Due to Nil Pointer Dereference in github.com/free5gc/udm2026-03-23vendor · osvUS
free5GC UDM DataChangeNotification Procedure Panic Due to Nil Pointer Dereference in github.com/free5gc/udm
also known as (5)
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sources
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references (13)
External citations — patches, advisories, analysis.
- https://github.com/free5gc/free5gc/issues/781cnnvd
- https://github.com/free5gc/free5gc/security/advisories/GHSA-7g27-v5wj-jr75cnnvd
- https://github.com/free5gc/udm/commit/65d7070f4bfd016864cbbaefbd506bbc85d2fa92cnnvd
- https://github.com/free5gc/udm/pull/78cnnvd
- https://github.com/free5gc/udm/releasesPatchcnnvd
- https://github.com/free5gc/free5gc/issues/781enisa_euvd
- https://github.com/free5gc/free5gc/security/advisories/GHSA-7g27-v5wj-jr75enisa_euvd
- https://github.com/free5gc/udm/commit/65d7070f4bfd016864cbbaefbd506bbc85d2fa92enisa_euvd
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