# HTTP.sys Denial of Service Vulnerability

CVE record · `CVE-2026-33096`

- **Identifiers:** `CVE-2026-33096`
- **State:** Confirmed
- **Severity:** CVSS 7.5 High
- **Critical:** No
- **CNA:** microsoft
- **Weakness (CWE):** [CWE-125](https://cwe.mitre.org/data/definitions/125.html)
- **Tags:** [Memory corruption](https://agentprime.io/advisories/tag/memory-corruption.md)
- **Technologies:** [Microsoft Windows 11 version 23H2](https://agentprime.io/advisories/technology/microsoft-windows-11-version-23h2.md) · [Microsoft Windows 11 Version 24H2](https://agentprime.io/advisories/technology/microsoft-windows-11-version-24h2.md) · [Microsoft Windows 11 Version 25H2](https://agentprime.io/advisories/technology/microsoft-windows-11-version-25h2.md) · [Microsoft Windows 11 version 26H1](https://agentprime.io/advisories/technology/microsoft-windows-11-version-26h1.md) · [Microsoft Windows Server 2022](https://agentprime.io/advisories/technology/microsoft-windows-server-2022.md) · [Microsoft Windows Server 2022, 23H2 Edition (Server Core installation)](https://agentprime.io/advisories/technology/microsoft-windows-server-2022-23h2-edition-server-core-installation.md) · [Microsoft Windows Server 2025](https://agentprime.io/advisories/technology/microsoft-windows-server-2025.md) · [Microsoft Windows Server 2025 (Server Core installation)](https://agentprime.io/advisories/technology/microsoft-windows-server-2025-server-core-installation.md)
- **Published:** 14 Apr 2026
- **Updated:** 15 Oct 2026
- **Reviewed by a person:** No

Published by the CVE Program (CNA: microsoft) at 14 Apr 2026, 16:57 UTC. agentprime has not analysed this yet, so whether it affects any app is not known. This CVE names a vendor and product rather than a package, so the lockfile check doesn’t match it.

## Affected products, as the CNA wrote them

- Vendor: Microsoft. Product: Windows 11 version 23H2.
  - affected: `10.0.22631.0 to before 10.0.22631.6936` (custom)
- Vendor: Microsoft. Product: Windows 11 Version 23H2.
  - affected: `10.0.22631.0 to before 10.0.22631.6936` (custom)
- Vendor: Microsoft. Product: Windows 11 Version 24H2.
  - affected: `10.0.26100.0 to before 10.0.26100.8246` (custom)
- Vendor: Microsoft. Product: Windows 11 Version 25H2.
  - affected: `10.0.26200.0 to before 10.0.26200.8246` (custom)
- Vendor: Microsoft. Product: Windows 11 version 26H1.
  - affected: `10.0.28000.0 to before 10.0.28000.1836` (custom)
- Vendor: Microsoft. Product: Windows Server 2022.
  - affected: `10.0.20348.0 to before 10.0.20348.5020` (custom)
- Vendor: Microsoft. Product: Windows Server 2022, 23H2 Edition (Server Core installation).
  - affected: `10.0.25398.0 to before 10.0.25398.2274` (custom)
- Vendor: Microsoft. Product: Windows Server 2025.
  - affected: `10.0.26100.0 to before 10.0.26100.32690` (custom)
- Vendor: Microsoft. Product: Windows Server 2025 (Server Core installation).
  - affected: `10.0.26100.0 to before 10.0.26100.32690` (custom)

## Not analysed yet

We haven’t published our own analysis of this CVE. If a person reviews it, this page will say what’s affected and what has to be true for it to matter.

## Severity and exploitation

- 7.5 High, CVSS 3.1: `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C`, from CNA (microsoft)

- **CISA KEV:** Not listed.
- **EPSS:** 0.012, the 69th percentile, on 5 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

## Timeline

This record came from the full history of the CVE Program, published 14 Apr 2026. New records show when each source confirmed them.

## Sources

- [CVE List: CVE-2026-33096](https://www.cve.org/CVERecord?id=CVE-2026-33096)
- [NVD: CVE-2026-33096](https://nvd.nist.gov/vuln/detail/CVE-2026-33096)

### References from the CNA

- <https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-33096> (vendor-advisory, patch)

Facts on this page come from the CVE List as the CNA published them, with CVSS from the sources named above, CISA KEV and FIRST EPSS. Vendors, products and versions are shown as the CNA wrote them. We don’t reproduce the CVE’s description.

## Check whether this affects you

This CVE names a vendor and product rather than a package, so the lockfile check doesn’t match it. Compare the affected versions above with what you run.

- With the agentprime MCP server (<https://api.agentprime.io/mcp>), `get_advisory` returns this record and `search_advisories` finds related ones. Setup: <https://agentprime.io/mcp.md>
- As JSON: <https://api.agentprime.io/v1/advisories/CVE-2026-33096>
- Everything that needs attention now: <https://agentprime.io/advisories/critical.md>

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The web page: <https://agentprime.io/advisories/CVE-2026-33096/>. Everything for agents: <https://agentprime.io/llms.txt>.