SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityAnalyzed

CVE-2026-44318

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…

MEDIUM 5.3EPSS 0.27%

Does this matter?

Lower severity and a low EPSS score (0.27%). Track it; it rarely justifies an emergency change on its own.

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.

CVSS 3.1
5.3 MEDIUMCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
EPSS
0.27% probability · 19th percentile
CISA KEV
Not listed
Weakness
CWE-362, CWE-820
Affected
free5gc/free5gc
Source
security-advisories@github.com

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.