How severe is CVE-2026-47291?

CVE-2026-47291 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2026-47291 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 22% (97th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-47291?

CVE-2026-47291 primarily affects Microsoft Windows 10 1607. In total, 24 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2026-47291?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

Does CVE-2026-47291 have an EU (EUVD) identifier?

Yes. CVE-2026-47291 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-35501.

When was CVE-2026-47291 published?

CVE-2026-47291 was published on 2026-06-09 and last updated on 2026-06-17.

CVE-2026-47291

CVE-2026-47291 is a critical-severity vulnerability in Microsoft Windows 10 1607 with a CVSS 3.x base score of 9.8. Its EPSS exploit-prediction score of 22% places it in the 97th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-122.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
EPSS exploit prediction: 22% (97th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-35501
Weakness: CWE-122
Affected product: Microsoft Windows 10 1607
Published: 2026-06-09
Last modified: 2026-06-17

Description

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

Frequently asked questions

What is CVE-2026-47291?: Integer overflow or wraparound in Windows HTTP.sys allows an unauthorized attacker to execute code over a network.
How severe is CVE-2026-47291?: CVE-2026-47291 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-47291 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 22% (97th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-47291?: CVE-2026-47291 primarily affects Microsoft Windows 10 1607. In total, 24 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2026-47291?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
Does CVE-2026-47291 have an EU (EUVD) identifier?: Yes. CVE-2026-47291 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-35501.
When was CVE-2026-47291 published?: CVE-2026-47291 was published on 2026-06-09 and last updated on 2026-06-17.

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-47291

Affected products (24)

cpe:2.3:o:microsoft:windows_10_1607:*:*:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_10_1607:*:*:*:*:*:*:x86:*
cpe:2.3:o:microsoft:windows_10_1809:*:*:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_10_1809:*:*:*:*:*:*:x86:*
cpe:2.3:o:microsoft:windows_10_21h2:*:*:*:*:*:*:arm64:*
cpe:2.3:o:microsoft:windows_10_21h2:*:*:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_10_21h2:*:*:*:*:*:*:x86:*
cpe:2.3:o:microsoft:windows_10_22h2:*:*:*:*:*:*:arm64:*
cpe:2.3:o:microsoft:windows_10_22h2:*:*:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_10_22h2:*:*:*:*:*:*:x86:*
cpe:2.3:o:microsoft:windows_11_23h2:*:*:*:*:*:*:arm64:*
cpe:2.3:o:microsoft:windows_11_23h2:*:*:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_11_24h2:*:*:*:*:*:*:arm64:*
cpe:2.3:o:microsoft:windows_11_24h2:*:*:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_11_25h2:*:*:*:*:*:*:arm64:*
cpe:2.3:o:microsoft:windows_11_25h2:*:*:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_11_26h1:*:*:*:*:*:*:arm64:*
cpe:2.3:o:microsoft:windows_11_26h1:*:*:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_server_2012:-:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2012:r2:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2016:*:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2019:*:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2022:*:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2025:*:*:*:*:*:*:x64:*

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