CVE-2026-17598 in Nexus Repository
Summary
by MITRE • 08/07/2026
Sonatype Nexus Repository 3 did not properly filter internal configuration keys from user-supplied task properties when creating or updating a scheduled task through the administrative UI. An account holding permission to create at least one scheduled task type could supply a crafted property value that caused the system to overwrite the configuration of an unrelated, existing task instead of creating a new one.
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Analysis
by VulDB Data Team • 08/07/2026
This vulnerability exists within Sonatype Nexus Repository 3's administrative interface where insufficient input validation allows privilege escalation through task management operations. The flaw stems from improper sanitization of user-supplied parameters during scheduled task creation and modification processes, enabling attackers to manipulate internal configuration keys that should remain protected from external influence. When a user with minimal task creation permissions submits crafted property values, the system fails to properly isolate these inputs, leading to potential cross-contamination between task configurations.
The technical implementation reveals that the system does not adequately distinguish between legitimate user-provided properties and internal system configuration parameters during task processing. This lack of proper filtering allows an attacker to inject malicious values that reference existing task identifiers or configuration elements, effectively enabling them to overwrite or modify unrelated scheduled tasks within the repository management system. The vulnerability manifests specifically when creating or updating scheduled tasks through the web-based administrative interface, where input validation occurs at an insufficient granularity level.
Operationally, this vulnerability represents a significant security risk as it allows attackers with basic task creation permissions to potentially disrupt critical repository operations or escalate their privileges. An attacker could overwrite existing backup schedules, modify security-related task configurations, or manipulate scheduled maintenance operations that affect the entire repository infrastructure. The impact extends beyond simple data manipulation since these tasks often control critical automated processes such as garbage collection, replication, or security scanning operations that maintain repository integrity and availability.
The vulnerability aligns with CWE-20 Input Validation and CWE-79 Cross-Site Scripting categories, where insufficient validation allows attackers to inject malicious parameters that affect system behavior. From an adversarial perspective, this flaw maps to ATT&CK technique T1078 Valid Accounts, as it leverages existing permissions to perform unauthorized modifications, and T1543 Create or Modify System Process, since the affected tasks often control automated repository operations. Organizations using Nexus Repository 3 should implement immediate mitigations including enhanced input validation for task properties, proper isolation of internal configuration parameters, and comprehensive access controls that limit task modification privileges to trusted administrators only.
Mitigation strategies must include implementing strict parameter filtering mechanisms that prevent user inputs from containing reserved or internal configuration keywords, establishing robust input sanitization routines during task creation and modification operations, and conducting regular security reviews of administrative interfaces. Organizations should also consider implementing additional monitoring for task modification activities and establishing privileged access controls that enforce the principle of least privilege for all repository management operations. The fix requires comprehensive code review of the task management module to ensure proper separation between user-facing parameters and internal system configuration elements, with particular attention to how these values are processed and stored within the repository's configuration database.