Vulnerabilities
CVE‑2026‑83515: RPC Runtime Information Disclosure in Windows
Microsoft has disclosed an information‑disclosure flaw in the RPC Runtime that can be triggered by an unauthenticated network attacker. The vulnerability allows reading of uninitialized memory, potentially exposing sensitive data. Apply the latest security update and review RPC service exposure.
What Happened
A flaw in the Windows RPC Runtime allows an attacker to read uninitialized memory over the network. The issue arises from improper handling of a resource that is not fully initialized before use.
Affected Systems
All Windows operating systems that expose RPC services, including Windows Server 2016/2019/2022, Windows 10, and Windows 11, are potentially vulnerable until patched.
Impact
The vulnerability can lead to disclosure of sensitive information such as configuration data, credentials, or other memory contents. It does not provide code execution or privilege escalation.
Mitigation
- Install the latest cumulative update that contains the RPC Runtime fix (see Microsoft Security Update Guide).
- Disable or restrict RPC services that are not required for your environment.
- Apply network segmentation and firewall rules to limit inbound traffic to RPC ports (TCP 135, 139, 445).
- Verify that the patch has been applied by checking the update history or running the Windows Update Agent API.
Additional Recommendations
Monitor event logs for RPC-related anomalies and conduct regular vulnerability scans to confirm the patch status. Keep all systems updated and review third‑party applications that rely on RPC for potential exposure.
Related vulnerabilities
CVE-2026-69803: Windows DHCP Server Information Disclosure
Microsoft has acknowledged CVE-2026-69803, an information disclosure flaw in the Windows DHCP Server that could allow attackers to read sensitive data. The vulnerability is currently unpatched; defenders should monitor for updates and limit DHCP exposure.
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CVE-2026-108462: Windows Kernel Information Disclosure Vulnerability
Microsoft has identified a Windows kernel information disclosure flaw (CVE‑2026‑108462) that permits local attackers with elevated privileges to read sensitive system data. The issue is fixed in the latest security update; administrators should apply the patch immediately and verify that kernel memory is protected.
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CVE-2026-83518: RPC Runtime Heap Overflow Enables Local Privilege Escalation on Windows
A heap-based buffer overflow in the Windows RPC Runtime (CVE‑2026‑83518) allows an attacker with local access to gain elevated privileges. The flaw is exploitable only by users who already have some level of access, making it a targeted privilege‑escalation vector. Defenders should apply the latest Microsoft patch, enforce least‑privilege policies, and monitor for anomalous local privilege changes.
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CVE-2026-70063: Local Windows Kernel Information Disclosure Vulnerability
Microsoft has identified CVE-2026-70063, an out‑of‑bounds read in the Windows kernel that permits a local, authorized attacker to read sensitive memory. The flaw is fixed in the latest cumulative update for Windows 10, Windows 11, and Windows Server 2022. Defenders should verify that the update is installed and monitor for any anomalous local privilege activity.
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