# CVE-2026-119128: ZITADEL authentication bypass in Login V2 UI

Source: https://junglewise.ai/threats/cve-2026-119128-zitadel-4-0-0-before-4-19-5-contains-an-authentication-bypass  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-29. Updated: 2026-10-29  
License: CC BY 4.0 with a link back

CVE-2026-119128 · Severity: high · CVSS 7.4 · Published 2026-10-29

ZITADEL is an identity and access management platform that handles user authentication and sign-in for applications. An attacker can forge a verification cookie to set a password, passkey, or link an external account for users who have not yet authenticated, taking over their accounts and gaining full access to ZITADEL and all connected applications.

Technologies: [ZITADEL](https://junglewise.ai/threats/technologies/zitadel). Vendors: [ZITADEL](https://junglewise.ai/threats/vendors/zitadel).

## Quick answers

**Is CVE-2026-119128 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-119128 being exploited in the wild.

**How severe is CVE-2026-119128?** High severity, with a CVSS score of 7.4, published 29 October 2026.

**Which products and versions are affected?** ZITADEL 4.0.0 through 4.19.4.

**Is there a fix for CVE-2026-119128?** Yes: fixed in 4.19.5. Until then: As a partial mitigation on unpatched versions, ensure all active users have an initial credential (password, passkey, or identity provider link) set so no user is left without an authentication method. The recommended solution is to upgrade to version 4.19.5 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-119128 attacked?** It is attacked over the network, in a hosted service.

**Am I affected by CVE-2026-119128?** Check whether you run ZITADEL at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- Fixed in 4.19.5

As a partial mitigation on unpatched versions, ensure all active users have an initial credential (password, passkey, or identity provider link) set so no user is left without an authentication method. The recommended solution is to upgrade to version 4.19.5 or later.

## Technical details

A server-side vulnerability in ZITADEL's Login V2 UI accepts a verificationCheck cookie that proves email or invite code verification, but the cookie value is computed only from the user ID and browser fingerprint—both attacker-controllable or learnable values—without a server-side secret. Attackers can compute valid forged cookies for any user lacking authentication methods (no password, passkey, or identity provider link) to set credentials and gain account takeover through password, passkey, or identity provider linking flows.

## Affected products

- ZITADEL ZITADEL 4.0.0 through 4.19.4

## Timeline

- 2026-10-15: disclosed
- 2026-10-29: advisory
- 2026-10-29: patched: Version 4.19.5 released

## References

- [https://github.com/zitadel/zitadel/security/advisories/GHSA-84fg-x5h4-w8xv](https://github.com/zitadel/zitadel/security/advisories/GHSA-84fg-x5h4-w8xv)
- [https://www.vulncheck.com/advisories/zitadel-4.0.0-before-4.19.5-login-v2-account-takeover-via-forgeable-verificationcheck-cookie](https://www.vulncheck.com/advisories/zitadel-4.0.0-before-4.19.5-login-v2-account-takeover-via-forgeable-verificationcheck-cookie)

## Related threats

- [ZITADEL missing authorization in Login V2 device authorization](https://junglewise.ai/threats/cve-2026-119129-zitadel-3-0-0-through-3-4-15-and-4-0-0-before-4-19-5-contains-a)
- [ZITADEL Login V2 host header injection in password reset](https://junglewise.ai/threats/cve-2026-119127-zitadel-4-0-0-before-4-19-5-contains-a-host-header-injection)
- [ZITADEL privilege escalation in OIDC token exchange](https://junglewise.ai/threats/cve-2026-109374-zitadel-3-0-0-before-4-19-2-contains-a-privilege-escalation)
- [ZITADEL authentication bypass in Login V2 UI](https://junglewise.ai/threats/cve-2026-109373-zitadel-3-0-0-before-4-19-2-contains-an-authentication-bypass)
- [ZITADEL hosted Login V1 authentication bypass in username change](https://junglewise.ai/threats/cve-2026-109371-zitadel-3-0-0-before-4-18-0-contains-a-missing-authentication)