CVE-2026-56583 in MyCloud
Summary
by MITRE • 07/21/2026
HCL MyCloud was affected with Concurrent Login Vulnerability. It may increase the risk of unauthorized access, session hijacking, and account misuse.
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Analysis
by VulDB Data Team • 07/21/2026
The concurrent login vulnerability in HCL MyCloud represents a critical security flaw that undermines the authentication mechanisms designed to protect user sessions and account integrity. This vulnerability allows multiple simultaneous logins using the same credentials, creating an attack surface that significantly increases the risk of unauthorized access to sensitive data and systems. The flaw stems from inadequate session management controls that fail to properly track and restrict concurrent user sessions, enabling malicious actors to exploit this weakness for various nefarious activities including session hijacking and account takeovers.
From a technical perspective, this vulnerability operates by bypassing the standard session validation processes that should prevent multiple active connections from the same user account. The underlying issue typically manifests in the application's session handling code where authentication tokens are not properly invalidated or tracked when new login attempts occur from different devices or locations. This allows attackers to maintain access through one session while establishing another, effectively creating a persistent presence within the system that can be exploited for data exfiltration, privilege escalation, or further lateral movement. The vulnerability aligns with CWE-613, which specifically addresses insufficient session expiration and inadequate session management practices that leave systems vulnerable to concurrent access attacks.
The operational impact of this vulnerability extends far beyond simple unauthorized access, creating cascading security risks that can compromise entire organizational infrastructures. When attackers exploit concurrent login capabilities, they can engage in session hijacking activities that allow them to impersonate legitimate users without detection, potentially accessing sensitive business data, customer information, or proprietary assets. Account misuse becomes increasingly dangerous as the attacker can maintain persistent access while performing malicious activities such as data manipulation, privilege escalation, or establishing backdoors for future access. The vulnerability also creates challenges for security monitoring and incident response teams who must distinguish between legitimate concurrent usage and malicious activity, potentially leading to false negatives in threat detection systems.
Organizations using HCL MyCloud systems face significant risks from this vulnerability including potential regulatory compliance violations, financial losses from data breaches, and reputational damage from unauthorized access incidents. The attack surface expands considerably as the vulnerability can be exploited through various vectors including credential stuffing attacks, where attackers use compromised credentials across multiple sessions, or through session fixation techniques that exploit the lack of proper session token management. Security professionals should consider implementing additional authentication controls such as multi-factor authentication, session timeout mechanisms, and real-time session monitoring to mitigate these risks. The vulnerability also highlights the importance of adhering to ATT&CK framework principles for secure session management, particularly focusing on techniques related to credential access and persistence through improper session handling.
Mitigation strategies should include immediate implementation of session limiting controls that prevent concurrent logins from the same account, proper session token invalidation upon logout or timeout, and enhanced monitoring of unusual login patterns that may indicate exploitation attempts. Organizations should also consider deploying network segmentation controls to limit lateral movement capabilities once an attacker has gained access through this vulnerability. Regular security assessments and penetration testing should be conducted to identify similar session management flaws across the organization's infrastructure. The implementation of robust logging mechanisms that track all authentication events and session activities provides crucial forensic data for incident response efforts, while also supporting compliance requirements for audit trails and security monitoring activities.