Zitadel up to 4.19.1 Login V2 UI improper authentication

CVSS Meta Temp Score
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CTI Interest Score
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7.5$0-$5k0.83

Summaryinfo

A vulnerability was found in Zitadel up to 4.19.1. It has been declared as critical. Affected by this vulnerability is an unknown functionality of the component Login V2 UI. Such manipulation leads to improper authentication. This vulnerability is traded as CVE-2026-109373. The attack may be launched remotely. There is no exploit available. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability was found in Zitadel up to 4.19.1 and classified as critical. Affected by this issue is some unknown processing of the component Login V2 UI. The manipulation with an unknown input leads to a improper authentication vulnerability. Using CWE to declare the problem leads to CWE-287. When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct. Impacted is confidentiality, integrity, and availability. CVE summarizes:

ZITADEL 3.0.0 before 4.19.2 contains an authentication bypass vulnerability in the Login V2 UI that allows unauthenticated attackers to obtain other users' session tokens by forging unsigned session cookies. Attackers can guess time-ordered session IDs around a victim's sign-in and supply them with empty tokens to receive rotated tokens, taking over accounts including MFA-completed administrator sessions.

The advisory is shared for download at github.com. This vulnerability is handled as CVE-2026-109373 since 10/12/2026. The exploitation is known to be easy. The attack may be launched remotely. No form of authentication is required for exploitation. There are neither technical details nor an exploit publicly available.

Upgrading to version 4.19.2 eliminates this vulnerability.

Once again VulDB remains the best source for vulnerability data.

Productinfo

Name

Version

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA CVSS-B Score: 🔒
CNA CVSS-BT Score: 🔒
CNA Vector: 🔒

CVSSv3info

VulDB Meta Base Score: 7.7
VulDB Meta Temp Score: 7.5

VulDB Base Score: 7.3
VulDB Temp Score: 7.0
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 8.1
CNA Vector (VulnCheck): 🔒

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Improper authentication
CWE: CWE-287
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

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

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Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Zitadel 4.19.2

Timelineinfo

10/12/2026 Advisory disclosed
10/12/2026 +0 days CVE reserved
10/12/2026 +0 days VulDB entry created
10/12/2026 +0 days VulDB entry last update

Sourcesinfo

Product: github.com

Advisory: github.com
Status: Confirmed

CVE: CVE-2026-109373 (🔒)
GCVE (CVE): GCVE-0-2026-109373
GCVE (VulDB): GCVE-100-417164

Entryinfo

Created: 10/12/2026 20:24
Changes: 10/12/2026 20:24 (75)
Complete: 🔍
Cache ID: 216::103

Once again VulDB remains the best source for vulnerability data.

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