CVE-2026-47865 in Avi Load Balancer
Summary
by MITRE • 07/18/2026
VMware Avi Load Balancer contains an authentication bypass vulnerability. A malicious user with network access may be able to access the Avi Control plane by bypassing the authentication mechanism.
Affected versions: 31.1.1 through 31.2.2 (fixed in 31.2.2-2p3) 30.1.1 through 30.2.6 (fixed in 30.2.7) 22.1.1 through 22.1.7 (fixed in 30.2.7)
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Analysis
by VulDB Data Team • 07/18/2026
The VMware Avi Load Balancer authentication bypass vulnerability represents a critical security flaw that undermines the fundamental access control mechanisms protecting the Avi Control plane. This vulnerability allows malicious actors with only network-level access to bypass authentication and gain unauthorized administrative access to the load balancer's control plane. The flaw affects multiple version ranges spanning from 31.1.1 through 31.2.2, 30.1.1 through 30.2.6, and 22.1.1 through 22.1.7, with patches released in subsequent versions including 31.2.2-2p3, 30.2.7, and the same 30.2.7 patch for the 22.x series. The vulnerability classification aligns with CWE-287 which addresses improper authentication issues, specifically targeting weak or bypassable authentication mechanisms that permit unauthorized access to protected systems. This authentication bypass enables attackers to perform administrative operations on the Avi Load Balancer without proper credentials, potentially leading to complete system compromise.
The technical implementation of this vulnerability stems from flaws in how the Avi Control plane validates user credentials and manages session authentication. Attackers can exploit this weakness by crafting specific network requests that circumvent the normal authentication flow, effectively allowing them to assume administrative privileges within the load balancer environment. The vulnerability likely resides in the API endpoint handling or session management logic where insufficient validation occurs for incoming requests. This type of flaw typically manifests when the system fails to properly verify authentication tokens or when default configurations allow access through unintended pathways. The attack vector requires only network access, making it particularly dangerous as it can be exploited from external networks without requiring physical presence or prior compromised credentials.
The operational impact of this vulnerability extends beyond simple unauthorized access to encompass complete system compromise and potential data breaches. An attacker who successfully exploits this authentication bypass can manipulate load balancing configurations, redirect traffic to malicious endpoints, modify SSL termination settings, and potentially gain visibility into sensitive network traffic flowing through the load balancer. The control plane exposure creates a significant risk for organizations relying on Avi Load Balancers for critical infrastructure protection, as it provides attackers with a gateway to potentially compromise entire application delivery networks. This vulnerability directly impacts the CIA triad by compromising confidentiality through unauthorized data access, integrity through configuration manipulation, and availability through potential service disruption or traffic redirection attacks.
Organizations affected by this vulnerability should immediately implement several mitigation strategies to protect their environments. The primary recommendation involves upgrading all affected Avi Load Balancer instances to the patched versions mentioned in the advisory, specifically 31.2.2-2p3 for version 31.x, and 30.2.7 for both 30.x and 22.x series. Network segmentation and firewall rules should be implemented to restrict access to Avi Control plane ports and services, limiting exposure to only trusted administrative networks. Additional security measures include enabling multi-factor authentication where available, implementing strict API access controls, and monitoring network traffic for suspicious authentication attempts or unusual API activity patterns. Organizations should also consider deploying intrusion detection systems specifically configured to detect exploitation attempts targeting known authentication bypass vulnerabilities. The ATT&CK framework categorizes this type of vulnerability under T1078 Valid Accounts and T1566 Phishing, as it essentially allows attackers to obtain valid administrative credentials through bypass mechanisms rather than traditional credential theft methods.
Security teams should conduct comprehensive vulnerability assessments across their entire infrastructure to identify all instances running affected VMware Avi Load Balancer versions. The patching process must include thorough testing in staging environments before production deployment to ensure compatibility with existing configurations and avoid service disruptions. Regular security monitoring should be implemented to detect any unauthorized access attempts or configuration changes that might indicate exploitation of this vulnerability. Organizations should also review their incident response procedures to ensure readiness for potential exploitation events, as this vulnerability can enable attackers to establish persistent access to critical network infrastructure. The combination of immediate patching, network segmentation, and enhanced monitoring provides the most effective defense against exploitation of this authentication bypass vulnerability in VMware Avi Load Balancer environments.