What is the CVSS score of EUVD-2026-27323?

EUVD-2026-27323 has a CVSS 3.1 base score of 9.1 (Critical). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N. EPSS exploitation probability: 0.0%.

Which versions of Gambio GX4 are affected by EUVD-2026-27323?

Gambio GX4 e-commerce platform versions 4.0.0.0 through 4.9.2.0 contain a critical unauthenticated password reset bypass that permits attackers to take over any user account if the account ID is…

How to fix or mitigate EUVD-2026-27323?

Within 24 hours: Identify all Gambio GX4 installations and confirm version numbers (4.0.0.0-4.9.2.0 are vulnerable); disable or restrict access to password reset functionality if feasible. Within 7 days: Upgrade all affected Gambio instances to version 2024-02 v1.0.0 or later per vendor advisory; test functionality in staging before production deployment. Within 30 days: Conduct account security audit (review account creation logs, password change logs, and suspicious login activity for the past 90 days); reset passwords for high-privilege accounts and customer accounts with payment data access; enable multi-factor authentication for administrative accounts if available.

Gambio GX4 EUVD-2026-27323

| CVE-2026-34408 CRITICAL

Weak Password Recovery Mechanism for Forgotten Password (CWE-640)

2026-05-05 mitre

GHSA-338p-fcwm-8fgc

Authentication Bypass N A

9.1

CVSS 3.1 · NVD

Severity by source

NVD PRIMARY

9.1 CRITICAL

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

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

None

Lifecycle Timeline

Analysis Generated

May 06, 2026 - 20:30 vuln.today

CVSS changed

May 06, 2026 - 18:22 NVD

9.1 (CRITICAL)

CVE Published

May 05, 2026 - 00:00 nvd

CRITICAL 9.1

DescriptionCVE.org

An issue was discovered in Gambio 4.9.2.0 (patched in 2024-02 v1.0.0 for GX4 v4.0.0.0 to v4.9.2.0). The password reset function can be bypassed to set arbitrary passwords for arbitrary accounts if the ID is known.

AnalysisAI

Password reset bypass in Gambio GX4 e-commerce platform allows remote unauthenticated attackers to set arbitrary passwords for any user account when the account ID is known, leading to complete account takeover. Affects versions 4.0.0.0 through 4.9.2.0, patched in February 2024 security update (2024-02 v1.0.0). SSVC framework rates this as automatable with total technical impact despite EPSS score of 0.02%, indicating high severity for targeted attacks against Gambio installations. No active exploitation confirmed via CISA KEV, but authentication bypass primitives are frequently weaponized in e-commerce platforms.

Technical ContextAI

Gambio GX4 is a German e-commerce platform built on PHP. The vulnerability stems from CWE-640 (Weak Password Recovery Mechanism for Forgotten Password), indicating the password reset workflow fails to properly validate the relationship between the requesting user and the target account. The CVSS vector AV:N/AC:L/PR:N/UI:N indicates the flaw is exploitable over the network without authentication or user interaction. The reset mechanism likely uses predictable or enumerable account identifiers without proper authorization checks, session binding, or cryptographic tokens to verify the legitimacy of the reset request. This represents a fundamental authentication design flaw rather than an input validation issue.

RemediationAI

Apply Gambio security update 2024-02 v1.0.0 immediately for all GX4 installations running versions 4.0.0.0 through 4.9.2.0. Download and installation instructions are available at https://www.gambio.de/forum/threads/wichtiges-security-update-2024-02-v1-0-fuer-gx4-v4-0-0-0-bis-v4-9-2-0.50896/. If immediate patching is not feasible, implement compensating controls: disable the password reset functionality at the application or web server level until patching is complete (trade-off: legitimate users cannot recover passwords), monitor authentication logs for multiple password reset attempts against different account IDs (may generate false positives during legitimate bulk password resets), restrict access to password reset endpoints to known IP ranges if user base geography is predictable (reduces accessibility for mobile users). Post-remediation, force password resets for all user accounts created or modified after vulnerability disclosure, and audit authentication logs from February 2024 onward for suspicious password reset patterns. Review account ID generation mechanisms to prevent enumeration attacks that facilitate exploitation of similar vulnerabilities.