Vulnerabilities
CVE-2026-83671: Windows Hyper‑V Out‑of‑Bounds Read Enables Local Information Disclosure
A local attacker can exploit an out‑of‑bounds read in Windows Hyper‑V to read arbitrary memory, exposing sensitive data. The flaw is CVE‑2026‑83671 and is mitigated by applying the latest Windows update or disabling Hyper‑V on non‑essential systems.
What Happened
Microsoft identified CVE‑2026‑83671 as an out‑of‑bounds read in the Hyper‑V hypervisor. The vulnerability allows a privileged user on the host to read memory beyond intended bounds, potentially leaking confidential information.
Impact
Only users with local administrative or Hyper‑V management privileges can exploit the flaw. Successful exploitation can expose memory contents, including credentials, keys, or other sensitive data residing on the host.
What to Do
- Apply the latest Windows security update that contains the Hyper‑V fix.
- If Hyper‑V is not required, consider disabling the feature or removing the role.
- Restrict local administrative access to trusted personnel only.
- Monitor for anomalous memory access patterns or unexpected Hyper‑V activity.
Related vulnerabilities
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.
Read briefing
Windows iSCSI Out-of-Bounds Read Enables Local Information Disclosure (CVE‑2026‑69721)
Microsoft disclosed an out-of-bounds read flaw in the Windows iSCSI Initiator service that lets local users with sufficient privileges read sensitive memory. The vulnerability affects all Windows systems running iSCSI and can expose credentials or keys. Defenders should patch immediately, disable iSCSI if unused, and limit local privileges.
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CVE-2026-69967: Windows Overlay Filter Out‑of‑Bounds Read Enables Local Information Disclosure
Microsoft identified an out‑of‑bounds read in the Windows Overlay Filter that allows a local user to read protected memory. The flaw exists in Windows 10 and 11 and is fixed by the latest cumulative update. Administrators should apply the patch and verify service configuration immediately.
Read briefing
CVE-2026-108399: Local Privilege Escalation via Heap Overflow in Windows Hyper‑V
A heap‑based buffer overflow in Windows Hyper‑V permits a local attacker with authorized access to gain elevated privileges. The vulnerability exists in all current Hyper‑V releases and can be mitigated by applying the latest Microsoft security update or disabling Hyper‑V when not required.
Read briefing