GHSA-282g-fhmx-xf54 CVE-2026-27946 GO-2026-4572

ZITADEL Users Can Self-Verify Email/Phone via UpdateHumanUser API

Medium Go

Severity: 0.0 / 10; Medium · CVSS 4.0
Exploit chance (EPSS): 0.22%; Chance of exploitation in the next 30 days. Higher than 12.32% of scored vulnerabilities.
Known exploited: No; Not in CISA's catalog
Weakness: CWE-862 Missing Authorization
Fix: 4.11.1; Upgrade github.com/zitadel/zitadel to this version or later

Description

Summary

A vulnerability in Zitadel's self-management capability allowed users to mark their email and phone as verified without going through an actual verification process.

Impact

Zitadel provides an API for managing users. The API also allows users to self-manage their own data including updating the email and phone.

Due to an improper permission check, the API allowed setting the verified flag for the email and phone on the own user. This allows users to claim ownership of an email or phone they do not control and potentially bypass email-based security policies.

Note that when changing another user's email or phone, regardless of the verification flag, the permissions were correctly checked.

Affected Versions

Systems running one of the following versions are affected:

4.x: 4.0.0 through 4.11.0 (including RC versions)
3.x: 3.0.0 through 3.4.6 (including RC versions)
2.x: 2.43.0 through 2.71.19

Patches

The vulnerability has been addressed in the latest releases. The patch resolves the issue by requiring the correct permission in case the verification flag is provided and only allows self-management of the email address, resp. phone number itself.

4.x: Upgrade to >=4.11.1 3.x: Update to >=3.4.7 2.x: Update to >=3.4.7

Workarounds

The recommended solution is to upgrade to a patched version. If an upgrade is not possible, an action (v2) could be used to prevent setting the verification flag on the own user.

Questions

If you have any questions or comments about this advisory, please email us at security@zitadel.com

Credits

This vulnerability was identified by MhdAsfan during a security audit of a system utilizing Zitadel.

Affected versions

Go

Package	Vulnerable	Fixed in
github.com/zitadel/zitadel	`>= 4.0.0, < 4.11.1`	`4.11.1`
github.com/zitadel/zitadel	`>= 2.43.0, < 3.4.7`	`3.4.7`
github.com/zitadel/zitadel	`< 1.80.0-v2.20.0.20260225053417-0261536243e5`	`1.80.0-v2.20.0.20260225053417-0261536243e5`

How to fix

Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.

github.com/zitadel/zitadel Go → `4.11.1`

go

go get github.com/zitadel/zitadel@v4.11.1 && go mod tidy

Severity breakdown

CVSS 4.0 0.0

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:H/VA:N/SC:N/SI:H/SA:N

Attack vector: Network
Attack complexity: Low
Attack requirements: None
Privileges required: None
User interaction: Active
Confidentiality (vulnerable system): None
Integrity (vulnerable system): High
Availability (vulnerable system): None
Confidentiality (subsequent systems): None
Integrity (subsequent systems): High
Availability (subsequent systems): None

CVSS 3.1 6.5

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

Attack vector: Network
Attack complexity: Low
Privileges required: Low
User interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: High
Availability: None

Weakness

CWE-862: Missing Authorization

The product does not perform an authorization check when an actor attempts to access a resource or perform an action.

How to prevent it

Architecture and Design: Divide the product into anonymous, normal, privileged, and administrative areas. Reduce the attack surface by carefully mapping roles with data and functionality. Use role-based access control (RBAC) [REF-229] to enforce the roles at the appropriate boundaries. Note that this approach may not protect against horizontal authorization, i.e., it will not protect a user from attacking others with the same role.
Architecture and Design: Ensure that access control checks are performed related to the business logic. These checks may be different than the access control checks that are applied to more generic resources such as files, connections, processes, memory, and database records. For example, a database may restrict access for medical records to a specific database user, but each record might only be intended to be accessible to the patient and the patient's doctor [REF-7].
Architecture and Design: Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, consider using authorization frameworks such as the JAAS Authorization Framework [REF-233] and the OWASP ESAPI Access Control feature [REF-45].
Architecture and Design: For web applications, make sure that the access control mechanism is enforced correctly at the server side on every page. Users should not be able to access any unauthorized functionality or information by simply requesting direct access to that page. One way to do this is to ensure that all pages containing sensitive information are not cached, and that all such pages restrict access to requests that are accompanied by an active and authenticated session token associated with a user who has the required permissions to access that page.
System Configuration, Installation: Use the access control capabilities of your operating system and server environment and define your access control lists accordingly. Use a "default deny" policy when defining these ACLs.

References

Advisories

nvd.nist.gov/vuln/detail/CVE-2026-27946

Packages

github.com/zitadel/zitadel

Timeline

Feb 26, 2026 Published
Jun 17, 2026 Last updated by the source
Nov 1, 2026 Latest EPSS score

Advisory	Severity	Why it's related
GHSA-fgmf-7rf8-m6vf ZITADEL: Actions V1 sandbox escape: host file read via require()	High	Also affects github.com/zitadel/zitadel
GHSA-9993-rfwp-rhwf ZITADEL: MFA bypass via session reuse in Login V2	High	Also affects github.com/zitadel/zitadel
GHSA-v859-c572-qh5p ZITADEL: Improper Role Revocation on Granted Projects during Multiple Role Deletions	Medium	Also affects github.com/zitadel/zitadel
GHSA-jq8w-8q2f-ffm9 ZITADEL Users Can Self-Verify Email/Phone via API	High	Also affects github.com/zitadel/zitadel
GHSA-vrh8-c9cm-wh8v ZITADEL: Unauthorized Token Privilege Escalation in OAuth2 Token Exchange	High	Also affects github.com/zitadel/zitadel
GHSA-992q-9gwp-7r79 ZITADEL: Auto-linking by email: IdP-side email verification is not checked	Medium	Also affects github.com/zitadel/zitadel
GHSA-v77h-2w3m-94hx ZITADEL: Missing Token Expiration (`exp`) Validation in JWT IdP Provider	Medium	Also affects github.com/zitadel/zitadel
GHSA-g5h5-m4hm-xjrr ZITADEL: Missing Token Audience Validation (`aud`) in JWT IdP Provider	Medium	Also affects github.com/zitadel/zitadel

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