{"schemaVersion":3,"id":"CVE-2026-109371","aliases":["CGA-6f62-fp64-xp34","CGA-mrcq-wf7w-p4r4"],"status":"published","duplicateOf":null,"title":null,"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. 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Authentication for Critical Function","description":"The product does not perform any authentication for functionality that requires a provable user identity or consumes a significant amount of resources.","type":"weakness","status":"Draft","abstraction":"Base","likelihoodOfExploit":"High","url":"https://cwe.mitre.org/data/definitions/306.html"}],"affected":[{"vendor":"chainguard","product":"zitadel-3","name":"zitadel-3","label":"zitadel-3","ecosystem":"Chainguard","cpePart":null,"purl":"pkg:apk/chainguard/zitadel-3","purlType":"apk","versions":[{"text":"All versions","noFixRecorded":true,"fixedIn":null}],"versionsText":"All versions (No fix recorded)","eol":null,"hubHref":null},{"vendor":"zitadel","product":"zitadel","name":"zitadel","label":"zitadel","ecosystem":null,"cpePart":"a","purl":null,"purlType":null,"versions":[{"text":"≥ 3.0.0, < 4.18.0","noFixRecorded":false,"fixedIn":null}],"versionsText":"≥ 3.0.0, < 4.18.0","eol":null,"hubHref":"/vendor/zitadel/zitadel"}],"affectedCount":2,"eol":{"hasEol":false,"count":0},"references":[{"url":"https://github.com/zitadel/zitadel/security/advisories/GHSA-4hgj-wm6c-q7p2","label":"github.com/zitadel/zitadel/security/advisories/GHSA-4hgj-wm6c-q7p2","hostname":"github.com","tags":["Vendor Advisory"]},{"url":"https://www.vulncheck.com/advisories/zitadel-3.0.0-before-4.18.0-unauthenticated-username-change-via-login-v1","label":"www.vulncheck.com/advisories/…","hostname":"www.vulncheck.com","tags":["Third Party Advisory"]}],"lineage":{"upstream":[],"downstream":[],"duplicates":[],"related":[]},"timeline":[{"kind":"published","date":"2026-10-12T16:05:44.304Z","label":"Published","detail":"Vulnerability first disclosed.","source":null},{"kind":"modified","date":"2026-10-15T02:55:04.399Z","label":"Last modified","detail":"Vulnerability information 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