{"id":"CVE-2026-44328","state":"PUBLISHED","title":"free5GC: SMF UPI DELETE /upi/v1/upNodesLinks/{ref} panics on AN-node deletion via nil UPF dereference; unauthenticated, state-mutating","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. 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.","publishedAt":"2026-05-27T15:39:44.153Z","updatedAt":"2026-05-27T17:42:00.534Z","severity":{"score":8.2,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H","source":"GitHub_M"},"assigner":"GitHub_M","products":["free5gc free5gc"],"affected":[{"vendor":"free5gc","product":"free5gc","versions":[{"version":"< 4.2.2","status":"affected"}]}],"references":["https://github.com/free5gc/free5gc/security/advisories/GHSA-p9mg-74mg-cwwr","https://github.com/free5gc/free5gc/issues/905","https://github.com/free5gc/smf/pull/199","https://github.com/free5gc/smf/commit/b57bc48081c3d3a2f333d02eb78e4fd31a120deb"],"weaknesses":["CWE-306","CWE-476","CWE-862"],"ingestedAt":"2026-10-29T20:11:57.932Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/44xxx/CVE-2026-44328.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-44328","state":"PUBLISHED","datePublished":"2026-05-27T15:39:44.153Z","dateUpdated":"2026-05-27T17:42:00.534Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-05-05T19:00:06.023Z"},"containers":{"cna":{"title":"free5GC: SMF UPI DELETE /upi/v1/upNodesLinks/{ref} panics on AN-node deletion via nil UPF dereference; unauthenticated, state-mutating","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"free5gc","product":"free5gc","versions":[{"version":"< 4.2.2","status":"affected"}]}],"references":[{"url":"https://github.com/free5gc/free5gc/security/advisories/GHSA-p9mg-74mg-cwwr","name":"https://github.com/free5gc/free5gc/security/advisories/GHSA-p9mg-74mg-cwwr","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/free5gc/free5gc/issues/905","name":"https://github.com/free5gc/free5gc/issues/905","tags":["x_refsource_MISC"]},{"url":"https://github.com/free5gc/smf/pull/199","name":"https://github.com/free5gc/smf/pull/199","tags":["x_refsource_MISC"]},{"url":"https://github.com/free5gc/smf/commit/b57bc48081c3d3a2f333d02eb78e4fd31a120deb","name":"https://github.com/free5gc/smf/commit/b57bc48081c3d3a2f333d02eb78e4fd31a120deb","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"HIGH","baseScore":8.2,"baseSeverity":"HIGH","confidentialityImpact":"NONE","integrityImpact":"LOW","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-306","lang":"en","description":"CWE-306: Missing Authentication for Critical Function","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-476","lang":"en","description":"CWE-476: NULL Pointer Dereference","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-862","lang":"en","description":"CWE-862: Missing Authorization","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-05-27T15:39:44.153Z"},"source":{"advisory":"GHSA-p9mg-74mg-cwwr","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","references":[{"url":"https://github.com/free5gc/free5gc/security/advisories/GHSA-p9mg-74mg-cwwr","tags":["exploit"]},{"url":"https://github.com/free5gc/free5gc/issues/905","tags":["exploit"]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-05-27T17:41:28.346248Z","id":"CVE-2026-44328","options":[{"Exploitation":"poc"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-05-27T17:42:00.534Z"}}]}}}