CVE-2026-47291: HTTP.sys Remote Code Execution Vulnerability
Integer overflow or wraparound in Windows HTTP.sys allows an unauthorized attacker to execute code over a network.
CSIRTS triage
- What
- Integer overflow or wraparound allows an unauthorized attacker to execute code over a network.
- Who is affected
- All deployments of Windows HTTP.sys.
- Urgency
- Remediation is critical due to high severity and potential for remote code execution.
- Action
- Apply the latest security updates from Microsoft.
AI-assisted analysis generated from the source advisory — verify against the original.
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Details
Original advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-47291
Exploitation outlook
EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.
- Elevated exploitation riskCVE-2026-4729122.8% 30-day exploitation probability — well above the norm. Schedule remediation this cycle. Riskier than 98% of all EPSS-scored CVEs.
Referenced CVEs
| CVE | CSIRTS overview | External |
|---|---|---|
| CVE-2026-47291 | coverage & exploitation status | NVD · CVE.org |
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