Description
free5GC is an open-source implementation of the 5G core network. Prior to 4.2.2, free5GC's BSF PUT /nbsf-management/v1/subscriptions/{subId} handler has an unsynchronized write on the global Subscriptions map. The handler first reads the map under RLock() via BSFContext.GetSubscription(subId), but if the subscription does not exist, ReplaceIndividualSubcription() writes back to the same map directly without taking the mutex (bsfContext.BsfSelf.Subscriptions[subId] = subscription). Under concurrent authenticated PUT load, one goroutine can read while another writes the map, which causes the Go runtime to abort the process with fatal error: concurrent map read and map write (Go runtime panics that come from concurrent map access bypass recover() and terminate the process). The BSF container exits with code 2 -- the entire BSF SBI surface goes down until restart. This vulnerability is fixed in 4.2.2.
Affected products
free5gc: free5gc
References6
- github.com/free5gc/free5gc/security/advisories/GHSA-27ph-8q4f-h… ExploitVendor Advisory
- github.com/free5gc/free5gc/security/advisories/GHSA-27ph-8q4f-h… ExploitVendor Advisory
- github.com/free5gc/bsf/commit/277908565fd628d974a13ef562b81a8b7… Patch
- github.com/free5gc/bsf/pull/7 Issue TrackingPatch
- github.com/free5gc/free5gc/issues/926 ExploitIssue Tracking
- github.com/free5gc/free5gc/issues/926 ExploitIssue Tracking
Metrics
- CVSS 3.1
-
5.3
MEDIUM
Score source: NVD
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H - EPSS — exploit probability
- 0% percentile: 27 · as of 14 November 2026
- CWE
- CWE-362CWE-820
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