ZITADEL 4.0.0 before 4.19.5 Login V2 Account Takeover via Forgeable verificationCheck Cookie

Summary

CVECVE-2026-119128
StatePUBLISHED
AssignerVulnCheck
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-10-29 16:18:05 UTC
Updated2026-11-03 16:17:21 UTC
DescriptionZITADEL 4.0.0 before 4.19.5 contains an authentication bypass vulnerability in the Login V2 UI that allows unauthenticated attackers to set the first credential of users lacking any authentication method. Attackers can compute a valid verificationCheck cookie from the user ID and browser fingerprint to set a password, register a passkey, or link an identity provider, taking over the account.

Risk And Classification

Primary CVSS: v4.0 9.1 CRITICAL from [email protected]

CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

EPSS: 0.002850000 probability, percentile 0.210700000 (date 2026-11-03)

Problem Types: CWE-565 | CWE-565 Reliance on Cookies without Validation and Integrity Checking


VersionSourceTypeScoreSeverityVector
4.0[email protected]Secondary9.1CRITICALCVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/C...
4.0CNACVSS9.1CRITICALCVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
3.1[email protected]Secondary7.4HIGHCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
3.1CNACVSS7.4HIGHCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N

CVSS v4.0 Breakdown

Attack Vector
Network
Attack Complexity
High
Attack Requirements
Present
Privileges Required
None
User Interaction
None
Confidentiality
High
Integrity
High
Availability
None
Sub Conf.
None
Sub Integrity
None
Sub Availability
None

CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

CVSS v3.1 Breakdown

Attack Vector
Network
Attack Complexity
High
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
None

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Zitadel Zitadel affected 4.0.0 4.19.5 semver Not specified
CNA Zitadel Zitadel unaffected 4.19.5 semver Not specified

References

ReferenceSourceLinkTags
www.vulncheck.com/advisories/zitadel-4.0.0-before-4.19.5-login-v2-account-takeo... [email protected] www.vulncheck.com
github.com/zitadel/zitadel/security/advisories/GHSA-84fg-x5h4-w8xv [email protected] github.com
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Vendor Comments And Credit

Discovery Credit

CNA: AdamKorcz (en)

CNA: peintnermax (en)

CNA: IAM-marco (en)

CNA: livio-a (en)

CNA: knQzx (en)

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