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. The POST /upi/v1/upNodesLinks create-or-update handler accepts attacker-controlled JSON and passes it directly into UpNodesFromConfiguration(), which calls logger.InitLog.Fatalf(...) on several validation failures. One confirmed path is the UE-IP-pool overlap check: a single unauthenticated POST that adds a new UPF whose pool overlaps an existing UPF terminates the entire SMF process (docker ps shows Exited (1)), not just the goroutine. This vulnerability is fixed in 4.2.2.
Metrics
Affected Vendors & Products
References
History
Thu, 28 May 2026 18:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| CPEs | cpe:2.3:a:free5gc:free5gc:*:*:*:*:*:*:*:* |
Thu, 28 May 2026 02:30:00 +0000
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| First Time appeared |
Free5gc
Free5gc free5gc |
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| Vendors & Products |
Free5gc
Free5gc free5gc |
Wed, 27 May 2026 18:30:00 +0000
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| Metrics |
ssvc
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Wed, 27 May 2026 16:30:00 +0000
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| Description | 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. The POST /upi/v1/upNodesLinks create-or-update handler accepts attacker-controlled JSON and passes it directly into UpNodesFromConfiguration(), which calls logger.InitLog.Fatalf(...) on several validation failures. One confirmed path is the UE-IP-pool overlap check: a single unauthenticated POST that adds a new UPF whose pool overlaps an existing UPF terminates the entire SMF process (docker ps shows Exited (1)), not just the goroutine. This vulnerability is fixed in 4.2.2. | |
| Title | free5GC: SMF UPI POST /upi/v1/upNodesLinks exits the SMF process on overlapping UE pools (unauthenticated, reachable Fatalf) | |
| Weaknesses | CWE-306 CWE-617 CWE-862 |
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| References |
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| Metrics |
cvssV3_1
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Status: PUBLISHED
Assigner: GitHub_M
Published: 2026-05-27T15:47:33.112Z
Updated: 2026-05-27T17:53:42.800Z
Reserved: 2026-05-05T19:00:06.022Z
Link: CVE-2026-44321
Updated: 2026-05-27T17:53:38.999Z
Status : Analyzed
Published: 2026-05-27T17:16:37.330
Modified: 2026-05-28T18:01:21.610
Link: CVE-2026-44321
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