CVE-2026-26190 is a critical vulnerability affecting Milvus, an open-source vector database designed for generative AI applications. The issue arises from the exposure of TCP port 9091 by default, allowing attackers to bypass authentication mechanisms. Specifically, the /expr debug endpoint utilizes a weak and predictable default authentication token derived from etcd.rootPath (default: by-dev), which leads to the potential for arbitrary expression evaluation. Furthermore, the full REST API (/api/v1/*) is accessible on the metrics/management port without any authentication, granting unauthenticated access to all business operations including data manipulation and credential management. This vulnerability has been addressed in versions 2.5.27 and 2.6.10.
The severity of this vulnerability is classified as critical, with a CVSS score of 9.8. The implications are severe, as attackers may leverage this vulnerability to gain unauthorized access to sensitive data and perform malicious actions. Organizations utilizing Milvus are urged to prioritize remediation efforts to mitigate the risk of exploitation, especially considering the vulnerability's potential impact on confidentiality, integrity, and availability.
As of now, there is no known public exploit or proof of concept available. However, the nature of the vulnerability suggests that it could be easily exploited by malicious actors. Organizations should act swiftly to ensure all systems are updated to the patched versions to prevent any unauthorized access.
Organizations should prioritize patching immediately. Given the critical nature of this vulnerability, it is essential for security teams to assess their deployments of Milvus and take necessary actions to secure their environments.
Vulnerability Details
The official CVE description states that prior to versions 2.5.27 and 2.6.10, Milvus exposes TCP port 9091 by default, enabling authentication bypasses. The weak default authentication token and the unrestricted access to the full REST API present significant security risks. The vulnerability is classified under CWE-306, indicating improper authentication.
The CVSS score of 9.8 categorizes this vulnerability as critical, reflecting the high potential for impact due to the ease of exploitation and the significant adverse effects on the confidentiality, integrity, and availability of the system.
Technical Analysis
The root cause of this vulnerability is the default configuration of Milvus that exposes sensitive endpoints without adequate authentication controls. The attack vector is network-based, requiring low complexity to exploit, as no privileges or user interactions are needed.
The vulnerability allows attackers to gain high levels of impact on confidentiality, integrity, and availability, making it critical for organizations to remediate this risk promptly.
Risk & Impact Analysis
Organizations utilizing Milvus need to understand the risk associated with CVE-2026-26190. The potential for unauthorized access to sensitive data and manipulation of critical operations poses a significant threat. The blast radius could impact not only the data stored within the Milvus database but also the overall integrity of the applications that depend on it.
The urgency of addressing this vulnerability is underscored by its critical CVSS score, highlighting the necessity for immediate action to prevent exploitation.
Exploitation Status
Signal | Status |
|---|---|
Known Exploit | No |
Public PoC | No |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
The affected versions of Milvus are all versions prior to 2.5.27 and 2.6.10. Organizations using these versions are strongly advised to upgrade to the latest patched versions to mitigate the risk of exploitation.
Mitigation & Remediation
To mitigate this vulnerability, organizations must immediately upgrade to Milvus versions 2.5.27 or 2.6.10. In addition, reviewing and hardening configurations to ensure that sensitive endpoints require proper authentication is crucial. Implementing monitoring to detect unauthorized access attempts can further enhance security.
For assistance in validating remediation efforts, organizations should consider engaging in penetration testing and vulnerability assessments.
Detection Guidance
Organizations should monitor logs for unusual access patterns, especially on the metrics/management port. Detecting any attempts to access the /expr endpoint or other sensitive operations without proper authentication should be prioritized.
AppSecure Threat Intelligence Insight
The long-term significance of CVE-2026-26190 underscores the need for robust authentication mechanisms in systems exposed to the internet. This vulnerability represents broader trends in security regarding the risks of misconfigured APIs and weak tokens. Security teams should reinforce the importance of secure coding practices and configuration management.
For further reading on securing your applications, refer to the following resources: API security best practices, penetration testing methodology, and vulnerability management program design to enhance your security posture.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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