CVE-2026-62818
Summary
by MITRE • 08/11/2026
Use after free in Active Directory Certificate Services (AD CS) allows an authorized attacker to execute code over a network.
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Analysis
by VulDB Data Team • 08/11/2026
The vulnerability described represents a critical use-after-free condition within Microsoft's Active Directory Certificate Services component that enables remote code execution under specific circumstances. This flaw exists in the certificate service implementation where improperly managed memory references allow attackers to manipulate heap memory structures and potentially execute arbitrary code on affected systems. The vulnerability specifically impacts environments where AD CS is deployed as a certificate authority, making it particularly dangerous in enterprise networks where certificate services are extensively utilized for authentication and encryption purposes.
The technical nature of this flaw stems from improper memory management within the certificate service processing pipeline where freed memory blocks are still referenced or accessed by subsequent operations. When legitimate certificate requests are processed through the AD CS infrastructure, certain error conditions or specific input parameters can trigger the release of memory resources while maintaining references to those locations. Attackers can exploit this by crafting malicious certificate requests that cause the system to access already-freed memory regions, potentially allowing them to control program execution flow and inject malicious code into the target process. This type of vulnerability maps directly to CWE-416 which specifically addresses use-after-free conditions in software implementations.
The operational impact of this vulnerability extends beyond simple privilege escalation as it provides attackers with persistent remote access capabilities within enterprise networks where certificate services are critical infrastructure components. Organizations utilizing AD CS for PKI operations face significant risk since compromised certificate authorities can potentially issue fraudulent certificates, enabling man-in-the-middle attacks and unauthorized system access. The attack vector requires minimal privileges to exploit since the vulnerability exists in the service processing layer that typically operates with elevated permissions. Network-based exploitation is possible without requiring local system access, making this particularly concerning for enterprise environments where certificate services are exposed to various network segments.
Mitigation strategies should focus on immediate patch deployment through Microsoft's security updates and proper network segmentation to limit exposure of AD CS components. Organizations must implement monitoring solutions that detect anomalous certificate request patterns or memory allocation behaviors within their PKI infrastructure. The implementation of certificate revocation lists and short certificate lifecycles can help reduce the window of opportunity for exploitation. Security teams should also consider deploying intrusion detection systems specifically tuned to monitor for use-after-free attack patterns in certificate service communications. Additional protective measures include restricting network access to certificate services, implementing strict certificate enrollment policies, and maintaining detailed audit logs of all certificate operations to enable rapid incident response when vulnerabilities are detected. This vulnerability demonstrates the critical importance of secure memory management practices in enterprise security infrastructure components as outlined in various security frameworks including those referenced by the mitre ATT&CK framework for privilege escalation and remote code execution techniques.