Vulnerability · Published May 27, 2026 · Assigned by GitHub_M
CVE-2026-44324free5GC: UDR nudr-dr DELETE amf-subscriptions panics on missing UE state via nil interface type assertion (single authenticated request)
Medium 6.5
In plain English
A medium-severity security flaw in free5gc from free5gc. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 36% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
free5GC is an open-source implementation of the 5G core network. Prior to 4.2.2, free5GC's UDR nudr-dr DELETE /subscription-data/{ueId}/{servingPlmnId}/ee-subscriptions/{subsId}/amf-subscriptions handler panics on a single authenticated request against a fresh UDR instance when the supplied ueId does not exist in UESubsCollection. The processor checks value, ok := udrSelf.UESubsCollection.Load(ueId) and sets a 404 USER_NOT_FOUND problem-details on the miss path, but execution continues and immediately runs value.(*udr_context.UESubsData) -- a Go type assertion on a nil interface, which panics with interface conversion: interface {} is nil, not *context.UESubsData. Gin recovery converts the panic into HTTP 500, but the endpoint remains repeatedly panicable. This vulnerability is fixed in 4.2.2.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Go | github.com/free5gc/udr | 1.4.3 | GHSA-jqfc-gwj5-3w63 |
| Go | github.com/free5gc/udr | 1.4.3 | GO-2026-5478 |
Affected products (as reported)
Weakness: CWE-704, CWE-754 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
References
- https://github.com/free5gc/free5gc/security/advisories/GHSA-jqfc-gwj5-3w63 x_refsource_CONFIRM
- https://github.com/free5gc/free5gc/issues/920 x_refsource_MISC
- https://github.com/free5gc/udr/pull/60 x_refsource_MISC
- https://github.com/free5gc/udr/commit/8a1d3c63be99d378806d771f086ff32f1867da99 x_refsource_MISC