Vulnerabilities
CVE-2026-83715: Windows Error Reporting Tampering Vulnerability
Microsoft identified a missing authentication check in Windows Error Reporting that allows a local attacker with authorized access to tamper with error reports. The flaw can be used to modify or delete diagnostic data, potentially masking malicious activity. Defenders should apply the latest security update and consider disabling WER on systems where it is not required.
What happened
Microsoft identified a missing authentication check in the Windows Error Reporting (WER) subsystem. The flaw permits an attacker who already has local authorized access to invoke a critical function without proper validation, enabling tampering of error report data.
Impact
Systems running any supported Windows OS are vulnerable. An attacker can modify or delete error reports, potentially hiding evidence of compromise or disrupting forensic investigations. The vulnerability does not provide remote code execution but can aid in cover‑up or persistence tactics.
What to do
- Apply the latest cumulative update that addresses CVE‑2026‑83715.
- For environments that do not rely on WER, disable the feature via Group Policy or registry (HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows\Windows Error Reporting).
- Audit WER configuration files and registry keys for unauthorized changes.
- Implement least‑privilege principles to limit local user capabilities.
Detection
Monitor for unexpected modifications to WER configuration files (e.g., WER.xml) and registry keys under HKLM\Software\Microsoft\Windows\Windows Error Reporting. Use integrity monitoring tools to alert on changes.
Related vulnerabilities
CVE-2026-83826: Windows Error Reporting Privilege Escalation Vulnerability
A local privilege escalation flaw in Windows Error Reporting allows an authenticated user to gain elevated rights by dereferencing an untrusted pointer. The issue affects all Windows 10/11 installations that have Error Reporting enabled. Apply the latest security update or disable the service to mitigate.
Read briefing
CVE-2026-69363: Windows Error Reporting Heap Overflow Enables Remote Privilege Escalation
A heap-based buffer overflow in Windows Error Reporting allows an authorized attacker to gain elevated privileges over a network. The flaw can be triggered by sending a crafted error report, enabling remote privilege escalation. Microsoft has issued a patch; administrators should apply updates and consider disabling or restricting Error Reporting.
Read briefing
CVE-2026-83748: Windows Error Reporting Remote Code Execution via Heap Overflow
A heap-based buffer overflow in Windows Error Reporting enables remote code execution by unauthenticated attackers. The flaw can be exploited over a network, allowing arbitrary code execution on affected systems. Apply the latest Microsoft security update or disable the Error Reporting service to mitigate the risk.
Read briefing
CVE‑2026‑83758: Windows Error Reporting Heap Overflow Enables Local Code Execution
A heap‑based buffer overflow in Windows Error Reporting can be triggered by an authorized user to run arbitrary code on the affected system. Microsoft has issued a patch; administrators should apply it or disable the service to mitigate.
Read briefing