{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-105207","assignerOrgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","state":"PUBLISHED","assignerShortName":"VulnCheck","dateReserved":"2026-10-04T13:02:21.188Z","datePublished":"2026-10-04T13:10:02.024Z","dateUpdated":"2026-10-04T13:10:02.024Z"},"containers":{"cna":{"providerMetadata":{"orgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","shortName":"VulnCheck","dateUpdated":"2026-10-04T13:10:02.024Z"},"datePublic":"2026-09-04T00:00:00.000Z","title":"ZITADEL before 4.17.3 Account Takeover via External IdP Linking","descriptions":[{"lang":"en","value":"ZITADEL 3.0.0 through 3.4.15 and 4.0.0 before 4.17.3 creates links between user accounts and external identity providers without verifying a primary factor or the caller's permission, including on identify-only Login V2 sessions and via the User Service V2 AddIDPLink endpoint. An unauthenticated attacker knowing a victim's login name can bind their own external IdP identity to the victim's account and then sign in as the victim."}],"problemTypes":[{"descriptions":[{"lang":"en","description":"Missing Authentication for Critical Function","cweId":"CWE-306","type":"CWE"}]}],"affected":[{"vendor":"zitadel","product":"zitadel","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","versionType":"semver","lessThan":"4.17.3"},{"version":"4.17.3","status":"unaffected","versionType":"semver"}]},{"vendor":"zitadel","product":"zitadel","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","versionType":"semver","lessThanOrEqual":"4.19.4"}]}],"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:a:zitadel:zitadel:*:*:*:*:*:*:*:*","versionEndExcluding":"4.17.3"}]}]},{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:a:zitadel:zitadel:*:*:*:*:*:*:*:*","versionEndIncluding":"4.19.4"}]}]}],"metrics":[{"format":"CVSS","cvssV4_0":{"version":"4.0","vectorString":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N","attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"NONE","userInteraction":"NONE","vulnConfidentialityImpact":"HIGH","vulnIntegrityImpact":"HIGH","vulnAvailabilityImpact":"HIGH","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","subAvailabilityImpact":"NONE","baseScore":9.3,"baseSeverity":"CRITICAL"}},{"format":"CVSS","cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH","baseScore":9.8,"baseSeverity":"CRITICAL"}}],"references":[{"url":"https://github.com/zitadel/zitadel/security/advisories/GHSA-g8gj-gq47-xgf4","tags":["vendor-advisory"],"name":"GitHub Security Advisory (GHSA-g8gj-gq47-xgf4)"},{"name":"VulnCheck Advisory: ZITADEL before 4.17.3 Account Takeover via External IdP Linking","tags":["third-party-advisory"],"url":"https://www.vulncheck.com/advisories/zitadel-before-4.17.3-account-takeover-via-external-idp-linking"}],"credits":[{"lang":"en","value":"lucasdodgson","type":"reporter"},{"lang":"en","value":"AdamKorcz","type":"reporter"},{"lang":"en","value":"grvijayan","type":"finder"},{"lang":"en","value":"livio-a","type":"finder"}],"x_generator":{"engine":"vulncheck-endgame"}}}}