CVE-2026-11403 in Nexus Repository Manager
Summary
by MITRE • 07/14/2026
A vulnerability in Sonatype Nexus Repository Manager's format-specific API key generation may allow a remote attacker to gain unauthorized access to repository operations as a targeted user. A format-specific API key realm (NuGet API Key, Docker Bearer Token, or npm Bearer Token) must be enabled and the targeted user must have an active API key for this vulnerability to be exploitable.
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Analysis
by VulDB Data Team • 07/14/2026
This vulnerability resides within Sonatype Nexus Repository Manager's API key generation mechanism, specifically affecting format-specific API key realms including NuGet API Keys, Docker Bearer Tokens, and npm Bearer Tokens. The flaw represents a security weakness that enables remote attackers to potentially impersonate targeted users and gain unauthorized access to repository operations. The vulnerability requires specific preconditions for exploitation to occur, namely that the affected format-specific API key realm must be enabled within the system configuration and the targeted user must possess an active API key for the vulnerable format. This dependency on specific configurations limits the attack surface but does not eliminate the risk entirely.
The technical nature of this vulnerability stems from improper validation or handling of API key generation processes within the repository manager's authentication framework. When users generate format-specific API keys, the system should maintain strict separation between different key types and ensure that each key operates within its designated scope without cross-contamination. The flaw likely manifests in how the system validates or authenticates these keys during repository operations, potentially allowing an attacker to manipulate or reuse keys across different formats. This represents a breakdown in the principle of least privilege and proper access control enforcement. Such vulnerabilities typically fall under CWE-284 Access Control Issues where insufficient controls allow unauthorized access to resources.
The operational impact of this vulnerability extends beyond simple unauthorized access, as it could enable attackers to manipulate repository contents, modify package versions, or even inject malicious artifacts into the software supply chain. Attackers could exploit this weakness to perform actions such as publishing new packages, modifying existing package metadata, or deleting repository components entirely. The implications are particularly severe in development environments where Nexus Repository Manager serves as a critical component for package distribution and dependency management. Organizations relying on these repositories for software delivery could face significant security risks including supply chain compromise, data integrity violations, and potential regulatory compliance issues. The vulnerability's remote exploitation capability means attackers can target systems without requiring physical access or local network presence.
Mitigation strategies should focus on immediate configuration reviews and implementation of additional security controls. Organizations must ensure that format-specific API key realms are properly configured with appropriate access restrictions and that regular audits of active API keys occur. Network segmentation and firewall rules should be implemented to limit access to Nexus Repository Manager instances from untrusted networks. The system should enforce strong authentication requirements including multi-factor authentication for administrative users, while also implementing automated monitoring for unusual API key usage patterns. Regular security updates and patches from Sonatype should be applied promptly, along with comprehensive testing of the patched configurations in non-production environments. Implementing proper logging and alerting mechanisms around API key generation and usage events will help detect potential exploitation attempts. This vulnerability aligns with ATT&CK techniques related to credential access and privilege escalation, specifically targeting the T1078 Valid Accounts and T1566 Phishing tactics where attackers may leverage compromised credentials for unauthorized repository access.