CVE-2026-17601 in Nexus Repository
Summary
by MITRE • 08/07/2026
A user holding a permission to update privilege definitions could modify a wildcard privilege already assigned to their own role to grant broader permissions than they were authorized to hold, including full administrative access, without any additional authorization check or role reassignment.
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Analysis
by VulDB Data Team • 08/07/2026
This vulnerability represents a critical privilege escalation flaw that undermines the core principles of least privilege and role-based access control within security frameworks. The issue stems from a design weakness in privilege management systems where users with the ability to update privilege definitions can manipulate existing permissions rather than simply creating new ones. When an attacker or malicious actor holds a role that includes wildcard privileges, they can exploit this vulnerability by modifying those wildcard entries to expand their access beyond their intended scope. This type of vulnerability directly relates to CWE-284 which describes improper access control mechanisms and specifically targets the weakness where authorization checks are bypassed during privilege modifications.
The technical implementation of this flaw typically occurs in systems that allow dynamic privilege assignment through direct manipulation of permission sets rather than through controlled administrative interfaces. When a user can modify their own role's wildcard privileges, they essentially gain the ability to redefine their access boundaries without requiring additional approval or validation processes. The vulnerability becomes particularly dangerous when wildcard patterns such as 'read:' or 'manage:' are used, as these can be modified to encompass all available system functions or resources. This modification bypasses standard authorization checks that would normally prevent a user from gaining elevated privileges without explicit administrative intervention.
The operational impact of this vulnerability extends far beyond simple unauthorized access, potentially enabling full system compromise and data exfiltration. An attacker exploiting this weakness could gradually expand their permissions until they achieve administrative control over the entire system or application. The lack of additional authorization checks means that even if the initial role assignment was properly constrained, subsequent modifications can completely undermine those security boundaries. This vulnerability also creates challenges for audit and compliance requirements since the unauthorized privilege expansion may not be immediately detectable through standard monitoring procedures.
Mitigation strategies must focus on implementing strict separation of duties and eliminating the ability for users to modify their own privilege definitions. Organizations should enforce mandatory authorization reviews for any changes to wildcard permissions, implement automated validation checks that prevent privilege escalation during modification operations, and establish audit trails that track all privilege modifications regardless of who performs them. The solution aligns with attack techniques described in the attack pattern taxonomy where adversaries leverage insufficient authorization controls to gain elevated privileges through role manipulation. Security implementations should also consider implementing principle of least privilege enforcement at the point of modification, ensuring that any changes to existing permissions cannot exceed the original authorization boundaries. Regular security assessments and privileged access reviews become essential components for detecting and preventing unauthorized privilege expansion attempts.