{"id":"CVE-2026-44321","title":"free5GC is an open-source implementation of the 5G core network","summary":"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 attack…","severity":"high","cvss":7.5,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","cwe":["CWE-306","CWE-617","CWE-862"],"vendor":"free5gc","product":"free5gc","affected":["free5gc < 4.2.2"],"patched":["free5gc 4.2.2"],"published":"2026-05-27","updated":"2026-10-14","sourceUpdated":"2026-10-14T20:10:00.190","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-44321","references":[{"url":"https://github.com/free5gc/free5gc/issues/906","label":"security-advisories@github.com"},{"url":"https://github.com/free5gc/free5gc/security/advisories/GHSA-44qj-cghf-9p97","label":"security-advisories@github.com"},{"url":"https://github.com/free5gc/smf/commit/e0974e07ddab44a67d36a563cca383b2449e33e5","label":"security-advisories@github.com"},{"url":"https://github.com/free5gc/smf/pull/203","label":"security-advisories@github.com"},{"url":"https://github.com/free5gc/free5gc/security/advisories/GHSA-44qj-cghf-9p97","label":"134c704f-9b21-4f2e-91b3-4a467353bcc0"}],"tags":["nvd"],"epss":0.00606,"epssPercentile":0.47745,"ingestedAt":"2026-10-14T20:53:12.330Z","slug":"CVE-2026-44321","body":"## Overview\n\nfree5GC 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.\n\n## Affected\n\n- `free5gc < 4.2.2`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `free5gc 4.2.2`","depth":"twilight","depthScore":41,"depthScoreParts":{"impact":41.3,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}