What is CVE-2026-47291?

CVE-2026-47291 is a critical-severity vulnerability in Microsoft Windows_10_1607, classified under Heap-based Buffer Overflow. CVSS score: 9.8/10. Published 2026-06-09.

How severe is CVE-2026-47291?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Buffer overflow in Microsoft Windows_10_1607

CVE-2026-47291

Integer overflow or wraparound in Windows HTTP.sys allows an unauthorized attacker to execute code over a network.

Vulnerability class: Buffer Overflow

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

Affected products

Microsoft Windows_10_1607
Microsoft Windows_10_1809
Microsoft Windows_10_21h2
Microsoft Windows_10_22h2
Microsoft Windows_11_23h2
Microsoft Windows_11_24h2
Microsoft Windows_11_25h2
Microsoft Windows_11_26h1
Microsoft Windows_server_2012 — versions r2
Microsoft Windows_server_2016

Weakness classification (CWE)

CWE-122 — Heap-based Buffer Overflow
CWE-190 — Integer Overflow or Wraparound

References

secure@microsoft.com (Vendor Advisory)

Frequently asked questions

What is CVE-2026-47291?: CVE-2026-47291 is a critical-severity vulnerability in Microsoft Windows_10_1607, classified under Heap-based Buffer Overflow. CVSS score: 9.8/10. Published 2026-06-09.
How severe is CVE-2026-47291?: Critical severity. CVSS v3 base score is 9.8 out of 10.