{"id":"CVE-2026-109371","revision":"76d77b9a048c4cd998a6dafaf29adeb6","records":[{"revision":"76d77b9a048c4cd998a6dafaf29adeb6","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-109371","aliases":[],"title":"ZITADEL 3.0.0 before 4.18.0 Unauthenticated Username Change via Login V1","description":"ZITADEL 3.0.0 before 4.18.0 contains a missing authentication vulnerability in the hosted Login V1 UI, where the change-username handler acts on the account bound to a login flow before any factor is verified. Unauthenticated attackers can submit a victim's login name and then post a new username to rename any active human user, including administrators, locking them out.","state":0,"publishedAt":"2026-10-12T16:05:44.304+00:00","modifiedAt":"2026-10-15T02:55:04.399+00:00","affected":[{"ecosystem":"Vendor product","name":"zitadel","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"vendor\": \"zitadel\",\n                    \"product\": \"zitadel\",\n                    \"defaultStatus\": \"unaffected\",\n                    \"packageURL\": \"pkg:golang/github.com/zitadel/zitadel\",\n                    \"versions\": [\n                        {\n                            \"version\": \"3.0.0\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"semver\",\n                            \"lessThan\": \"4.18.0\"\n                        },\n                        {\n                            \"version\": \"4.18.0\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 4.0","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:L/SC:N/SI:N/SA:N","score":8.8,"severity":"HIGH"},{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:L","score":8.2,"severity":"HIGH"}],"references":["https://github.com/zitadel/zitadel/security/advisories/GHSA-4hgj-wm6c-q7p2","https://www.vulncheck.com/advisories/zitadel-3.0.0-before-4.18.0-unauthenticated-username-change-via-login-v1"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-109371","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-109371","identifiers":["CVE-2026-109371"]},"retained":false,"historicalAffected":[]}],"coverage":[]}