VDB-377572 · CVE-2026-55671 · GCVE-0-2026-55671

ZITADEL up to 4.15.1 Denylist dns rebinding

CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	Current Exploit Price (≈) Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.	CTI Interest Score Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
6.0	$0-$5k	0.00

Summaryinfo

A vulnerability was found in ZITADEL up to 4.15.1. It has been declared as critical. This affects an unknown function of the component Denylist. Executing a manipulation can lead to dns rebinding. This vulnerability is tracked as CVE-2026-55671. The attack can be launched remotely. No exploit exists.

Detailsinfo

A vulnerability has been found in ZITADEL up to 4.15.1 and classified as critical. This vulnerability affects some unknown processing of the component Denylist. The manipulation with an unknown input leads to a dns rebinding vulnerability. The CWE definition for the vulnerability is CWE-350. The product performs reverse DNS resolution on an IP address to obtain the hostname and make a security decision, but it does not properly ensure that the IP address is truly associated with the hostname. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

ZITADEL is an open source identity management platform. From 4.0.0-rc.1 through 4.15.1, ZITADEL's HTTP notification channels, OIDC BackChannel Logout, and SAML metadata URL fetches do not consistently validate user-defined URLs against protected denylist handling, allowing server-side requests to loopback, internal IP, link-local, or redirected endpoints through DNS rebinding, redirects, or protocol downgrades. This issue is fixed in version 4.15.2.

The advisory is shared for download at github.com. This vulnerability was named CVE-2026-55671 since 06/17/2026. The exploitation appears to be easy. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. Successful exploitation requires user interaction by the victim. There are neither technical details nor an exploit publicly available. The MITRE ATT&CK project declares the attack technique as T1583.002.

Upgrading to version 4.15.2 eliminates this vulnerability.

Once again VulDB remains the best source for vulnerability data.

Productinfo

Name

ZITADEL

Version

Website

Product: https://github.com/zitadel/zitadel/

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.3
VulDB Meta Temp Score: 6.0

VulDB Base Score: 6.3
VulDB Temp Score: 6.0
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AV	AC	Au	C	I	A
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💳	💳	💳	💳	💳	💳
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Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Dns rebinding
CWE: CWE-350
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: no mitigation known
Status: 🔍

0-Day Time: 🔒

Upgrade: ZITADEL 4.15.2

Timelineinfo

06/17/2026 CVE reserved
07/10/2026 +23 days Advisory disclosed
07/10/2026 +0 days VulDB entry created
07/10/2026 +0 days VulDB entry last update

Sourcesinfo

Product: github.com

Advisory: github.com
Status: Confirmed

CVE: CVE-2026-55671 (🔒)
GCVE (CVE): GCVE-0-2026-55671
GCVE (VulDB): GCVE-100-377572

Entryinfo

Created: 07/10/2026 20:25
Changes: 07/10/2026 20:25 (52)
Complete: 🔍
Cache ID: 216::103