# CVE-2026-105206: ZITADEL incorrect authorization in User Service API

Source: https://junglewise.ai/threats/cve-2026-105206-zitadel-3-0-0-through-3-4-15-and-4-x-before-4-17-3-contains-an  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-04. Updated: 2026-10-05  
License: CC BY 4.0 with a link back

CVE-2026-105206 · Severity: info · Published 2026-10-04

ZITADEL is an identity and access management (IAM) platform that manages user authentication and authorization across organizations. An authentication flaw in the User Service API allows a member of one organization who holds user.read permissions to discover which authentication methods (passwords, passkeys, TOTP, etc.) have been registered by users in other organizations on the same instance, revealing the attack surface across organizational boundaries.

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

## Quick answers

**Is CVE-2026-105206 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-105206 being exploited in the wild.

**How severe is CVE-2026-105206?** Informational severity, published 4 October 2026.

**Which products and versions are affected?** ZITADEL 3.0.0 through 3.4.15, 4.0.0 through 4.17.2.

**Is there a fix for CVE-2026-105206?** Yes: fixed in ZITADEL 4.17.3 and later. Version 3.x is end-of-life; affected deployments must upgrade to 4.17.3 or later.. Until then: As a partial mitigation on unpatched versions, restrict which principals hold org-scoped user.read permissions (including ORG_OWNER_VIEWER and custom roles) to trusted operators only, and monitor for unexpected cross-organization user enumeration. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-105206 attacked?** It is attacked over the network, in a hosted service.

**Am I affected by CVE-2026-105206?** 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 ZITADEL 4.17.3 and later. Version 3.x is end-of-life; affected deployments must upgrade to 4.17.3 or later.

As a partial mitigation on unpatched versions, restrict which principals hold org-scoped user.read permissions (including ORG_OWNER_VIEWER and custom roles) to trusted operators only, and monitor for unexpected cross-organization user enumeration.

## Technical details

The vulnerability is an incorrect authorization flaw (CWE-863) in the GET /v2/users/{userId}/authentication_methods endpoint and its v2beta equivalent. The API verifies the caller's user.read permission against their own organization context rather than the organization that owns the target user. An authenticated attacker with org-scoped user.read in any organization can query other organizations' users via direct user ID and enumerate authentication method types across organizational boundaries. No secrets or credential material are exposed, and authentication methods cannot be modified.

## Affected products

- ZITADEL ZITADEL 3.0.0 through 3.4.15, 4.0.0 through 4.17.2

## Timeline

- 2026-10-04: disclosed
- 2026-10-04: patched: Fix released in 4.17.3

## References

- [https://github.com/zitadel/zitadel/security/advisories/GHSA-j344-gqv4-84ff](https://github.com/zitadel/zitadel/security/advisories/GHSA-j344-gqv4-84ff)
- [https://www.vulncheck.com/advisories/zitadel-before-4.17.3-cross-organization-authentication-method-enumeration-via-user-service](https://www.vulncheck.com/advisories/zitadel-before-4.17.3-cross-organization-authentication-method-enumeration-via-user-service)

## 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 authentication bypass in Login V2 UI](https://junglewise.ai/threats/cve-2026-119128-zitadel-4-0-0-before-4-19-5-contains-an-authentication-bypass)
- [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)