CVE-2026-17039 in Certificate System
Summary
by MITRE • 07/24/2026
A flaw was found in pki-core. The certificate authority (CA) renewal request path does not perform the realm-based authorization check that the enrollment path performs, allowing an authenticated user entitled to one realm to cause a certificate belonging to a different realm to be renewed without that realm's authorization.
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Analysis
by VulDB Data Team • 07/24/2026
This vulnerability exists within the pki-core component of a public key infrastructure system where certificate authority renewal requests lack proper realm-based authorization controls that are consistently enforced during the initial enrollment process. The flaw represents a privilege escalation issue that undermines the fundamental security model of multi-realm PKI deployments where different organizational units or domains maintain separate certificate management boundaries.
The technical implementation defect stems from inconsistent authorization logic where the enrollment pathway properly validates realm membership and permissions before issuing certificates, while the renewal pathway bypasses these checks entirely. This creates a scenario where an authenticated user who possesses valid credentials for one realm can exploit the system to extend the validity of certificates belonging to another realm without proper authorization. The vulnerability directly relates to CWE-284 Access Control Issues, specifically concerning insufficient authorization controls during certificate lifecycle management operations.
From an operational perspective this flaw allows for unauthorized certificate manipulation across administrative boundaries, potentially enabling attackers to maintain persistent access beyond their legitimate scope or to impersonate entities within other realms. The impact extends beyond simple certificate renewal as it compromises the integrity of the entire PKI trust model, particularly affecting systems that rely on realm-based isolation for security segmentation. This vulnerability is particularly concerning in enterprise environments where multiple business units or departments share a single PKI infrastructure but require strict separation of certificate management privileges.
The operational implications include potential certificate forgery scenarios, unauthorized access to protected resources, and compromise of audit trails that normally track certificate issuance and renewal activities across different administrative domains. Organizations may experience unauthorized certificate extensions that could be used to maintain long-term access to systems or services without proper authorization from the legitimate realm administrators. This vulnerability aligns with ATT&CK technique T1556 Credential Access through the exploitation of insufficient access controls during certificate lifecycle operations.
Mitigation strategies should include immediate implementation of realm-based authorization checks in the certificate renewal path, ensuring that all certificate management operations follow identical permission validation procedures regardless of the specific operation type. System administrators should implement additional monitoring for unauthorized certificate renewals and establish automated alerting mechanisms when certificates are extended outside their expected administrative boundaries. The fix requires comprehensive code review to ensure that all paths through the certificate authority processing logic enforce consistent authorization controls, with particular attention to the renewal versus enrollment code branches to eliminate the authorization gap that enables this vulnerability.