CVE-2026-17603 in Nexus Repository
Summary
by MITRE • 08/07/2026
Nexus Repository 3 did not sufficiently restrict which HikariCP connection-pool properties could be set through the DataStore configuration API. A user holding the nx-datastores-update permission could set the connectionInitSql property to execute arbitrary SQL against the configured database on every new connection. On the default H2 database backend, this could be leveraged to achieve remote code execution as the Nexus process user.
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Analysis
by VulDB Data Team • 08/07/2026
The vulnerability in Nexus Repository 3 represents a critical privilege escalation and remote code execution flaw that stems from insufficient input validation within the DataStore configuration API. This issue specifically affects the HikariCP connection pool implementation where certain properties are not properly restricted, allowing authenticated users with the nx-datastores-update permission to manipulate database connection parameters. The technical flaw manifests through the connectionInitSql property which is designed to execute SQL commands during connection initialization but becomes exploitable when set by unauthorized parties. This vulnerability directly maps to CWE-20: Improper Input Validation and falls under the ATT&CK technique T1068: Exploitation for Privilege Escalation.
The operational impact of this vulnerability extends beyond simple privilege escalation as it enables attackers to execute arbitrary SQL commands against the underlying database with elevated privileges. When Nexus Repository 3 utilizes the default H2 database backend, the attacker can leverage this weakness to achieve remote code execution as the Nexus process user, effectively compromising the entire repository infrastructure. The attack vector requires minimal privileges since only the nx-datastores-update permission is needed, making it particularly dangerous in environments where multiple administrators have access to this specific permission level. This represents a severe configuration management flaw where database connection parameters are not adequately sanitized or restricted, allowing malicious input to be interpreted as executable SQL commands.
The exploitation process involves setting the connectionInitSql property through the DataStore API endpoint, which then executes the specified SQL against every new database connection attempt. In H2 database environments, this capability can be leveraged to execute system commands, access sensitive data, or establish persistent access to the repository server. The vulnerability affects all versions of Nexus Repository 3 that utilize the HikariCP connection pool and default H2 backend configuration. Organizations using alternative database backends may be less immediately impacted but should still consider this as a potential attack surface for privilege escalation.
Mitigation strategies include restricting the nx-datastores-update permission to only trusted administrators, implementing proper input validation for all DataStore configuration parameters, and upgrading to versions that properly sanitize HikariCP connection properties. Organizations should also monitor database connection logs for suspicious SQL execution patterns and implement network-level restrictions to limit access to the DataStore API endpoint. Additionally, regular security assessments of repository configurations and privilege assignments are essential to prevent unauthorized users from obtaining the required permissions to exploit this vulnerability. The remediation process should include reviewing all DataStore configuration endpoints for similar input validation issues and implementing principle of least privilege across all administrative functions.