Vulnerability Details CVE-2026-44328
free5GC is an open-source implementation of the 5G core network. Prior to 4.2.2, free5GC's SMF mounts the UPI management route group without inbound OAuth2 middleware. On top of that, the DELETE /upi/v1/upNodesLinks/{upNodeRef} handler unconditionally dereferences upNode.UPF after the type-guarded async release, even though AN-typed nodes are constructed without a UPF object. As a result, a single unauthenticated DELETE /upi/v1/upNodesLinks/gNB1 request crashes the handler with a nil-pointer panic AND mutates the in-memory user-plane topology before panicking (the UpNodeDelete(upNodeRef) line runs first). This is an unauthenticated, state-mutating panic-DoS sink that an off-path network attacker can trigger by name against any AN entry. This vulnerability is fixed in 4.2.2.
Exploit prediction scoring system (EPSS) score
EPSS Score 0.001
EPSS Ranking 18.2%
CVSS Severity
CVSS v3 Score 8.2
Products affected by CVE-2026-44328
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cpe:2.3:a:free5gc:free5gc:1.1.1
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cpe:2.3:a:free5gc:free5gc:3.0.1
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cpe:2.3:a:free5gc:free5gc:3.0.2
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cpe:2.3:a:free5gc:free5gc:3.0.3
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cpe:2.3:a:free5gc:free5gc:3.0.4
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cpe:2.3:a:free5gc:free5gc:3.0.5
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cpe:2.3:a:free5gc:free5gc:3.0.6
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cpe:2.3:a:free5gc:free5gc:3.0.7
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cpe:2.3:a:free5gc:free5gc:3.1.0
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cpe:2.3:a:free5gc:free5gc:3.1.1
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cpe:2.3:a:free5gc:free5gc:3.2.0
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cpe:2.3:a:free5gc:free5gc:3.2.1
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cpe:2.3:a:free5gc:free5gc:3.3.0
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cpe:2.3:a:free5gc:free5gc:3.4.0
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cpe:2.3:a:free5gc:free5gc:3.4.1
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cpe:2.3:a:free5gc:free5gc:3.4.2
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cpe:2.3:a:free5gc:free5gc:3.4.3
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cpe:2.3:a:free5gc:free5gc:3.4.4
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cpe:2.3:a:free5gc:free5gc:3.4.5
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cpe:2.3:a:free5gc:free5gc:4.0.0
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cpe:2.3:a:free5gc:free5gc:4.0.1
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cpe:2.3:a:free5gc:free5gc:4.1.0