{"id":"CVE-2026-44321","summary":"free5GC: SMF UPI POST /upi/v1/upNodesLinks exits the SMF process on overlapping UE pools (unauthenticated, reachable Fatalf)","details":"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.","aliases":["GHSA-44qj-cghf-9p97","GO-2026-5109"],"modified":"2026-07-08T08:13:30.048508415Z","published":"2026-05-27T15:47:33.112Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/44xxx/CVE-2026-44321.json","cna_assigner":"GitHub_M","cwe_ids":["CWE-306","CWE-617","CWE-862"]},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/44xxx/CVE-2026-44321.json"},{"type":"ADVISORY","url":"https://github.com/free5gc/free5gc/security/advisories/GHSA-44qj-cghf-9p97"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-44321"},{"type":"REPORT","url":"https://github.com/free5gc/free5gc/issues/906"},{"type":"FIX","url":"https://github.com/free5gc/smf/commit/e0974e07ddab44a67d36a563cca383b2449e33e5"},{"type":"FIX","url":"https://github.com/free5gc/smf/pull/203"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/free5gc/free5gc","events":[{"introduced":"0"},{"fixed":"8b0f4445fc931638fb624463ce3572a203517679"}],"database_specific":{"source":["AFFECTED_FIELD","CPE_RANGE"],"extracted_events":[{"introduced":"0"},{"fixed":"4.2.2"}],"cpe":"cpe:2.3:a:free5gc:free5gc:*:*:*:*:*:*:*:*"}},{"type":"GIT","repo":"https://github.com/free5gc/smf","events":[{"introduced":"0"},{"fixed":"e0974e07ddab44a67d36a563cca383b2449e33e5"}],"database_specific":{"source":"REFERENCES"}}],"versions":["v4.2.1","v4.2.0","v4.1.0","v4.0.1","v4.0.0","v3.4.5","v3.4.4","v3.4.3","v3.4.2","v3.4.1","v3.4.0","v3.3.0","v3.2.1","v3.2.0","v3.1.1","v3.1.0","v3.0.7","v3.0.6","v3.0.5","v1.4.3","v1.4.2","v1.4.1","v1.4.0","v1.3.2","v1.3.1","v1.3.0","v1.2.7","v1.2.6","v1.2.5","v1.2.4","v1.2.3","v1.2.2","v1.2.1","v1.2.0","v1.1.1","v1.1.0","v1.0.2","v1.0.1","v1.0.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-44321.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"}]}