CVE-2018-8304 — A denial of service vulnerability exists in Windows Domain Name System (DNS) DNSAPI.dll when it fails to properly handle DNS responses, aka "Windows DNSAPI Denial of Service Vulnerability." This affects Windows 7, Windows Server 2012 R2, Windows RT 8.1, Windows Server 2008, Windows Server 2012, Windows 8.1, Windows Server 2016, Windows Server 2008 R2, Windows 10, Windows 10 Servers

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MEDIUM

A denial of service vulnerability exists in Windows Domain Name System (DNS) DNSAPI.dll when it fails to properly handle DNS responses, aka "Windows DNSAPI Denial of Service Vulnerability." This affects Windows 7, Windows Server 2012 R2, Windows RT 8.1, Windows Server 2008, Windows Server 2012, Windows 8.1, Windows Server 2016, Windows Server 2008 R2, Windows 10, Windows 10 Servers

Published Jul 11, 2018

5.9

MEDIUM

CVSS 3.0

EPSS 12.57%

Description

A denial of service vulnerability exists in Windows Domain Name System (DNS) DNSAPI.dll when it fails to properly handle DNS responses, aka "Windows DNSAPI Denial of Service Vulnerability." This affects Windows 7, Windows Server 2012 R2, Windows RT 8.1, Windows Server 2008, Windows Server 2012, Windows 8.1, Windows Server 2016, Windows Server 2008 R2, Windows 10, Windows 10 Servers.

Affected products

Vendor Microsoft Product Windows 10 Default
n/a
- Version
  32-bit Systems
  Status
  affected
  Constraints
  -
- Version
  Version 1607 for 32-bit Systems
  Status
  affected
  Constraints
  -
- Version
  Version 1607 for x64-based Systems
  Status
  affected
  Constraints
  -
- Version
  Version 1703 for 32-bit Systems
  Status
  affected
  Constraints
  -
- Version
  Version 1703 for x64-based Systems
  Status
  affected
  Constraints
  -
- Version
  Version 1709 for 32-bit Systems
  Status
  affected
  Constraints
  -
- Version
  Version 1709 for x64-based Systems
  Status
  affected
  Constraints
  -
- Version
  x64-based Systems
  Status
  affected
  Constraints
  -
Vendor Microsoft Product Windows 10 Servers Default
n/a
- Version
  version 1709 (Server Core Installation)
  Status
  affected
  Constraints
  -
Vendor Microsoft Product Windows 7 Default
n/a
- Version
  32-bit Systems Service Pack 1
  Status
  affected
  Constraints
  -
- Version
  x64-based Systems Service Pack 1
  Status
  affected
  Constraints
  -
Vendor Microsoft Product Windows 8.1 Default
n/a
- Version
  32-bit systems
  Status
  affected
  Constraints
  -
- Version
  x64-based systems
  Status
  affected
  Constraints
  -
Vendor Microsoft Product Windows RT 8.1 Default
n/a
- Version
  Windows RT 8.1
  Status
  affected
  Constraints
  -
Vendor Microsoft Product Windows Server 2008 Default
n/a
- Version
  32-bit Systems Service Pack 2
  Status
  affected
  Constraints
  -
- Version
  32-bit Systems Service Pack 2 (Server Core installation)
  Status
  affected
  Constraints
  -
- Version
  Itanium-Based Systems Service Pack 2
  Status
  affected
  Constraints
  -
- Version
  x64-based Systems Service Pack 2
  Status
  affected
  Constraints
  -
- Version
  x64-based Systems Service Pack 2 (Server Core installation)
  Status
  affected
  Constraints
  -
Vendor Microsoft Product Windows Server 2008 R2 Default
n/a
- Version
  Itanium-Based Systems Service Pack 1
  Status
  affected
  Constraints
  -
- Version
  x64-based Systems Service Pack 1
  Status
  affected
  Constraints
  -
- Version
  x64-based Systems Service Pack 1 (Server Core installation)
  Status
  affected
  Constraints
  -
Vendor Microsoft Product Windows Server 2012 Default
n/a
- Version
  (Server Core installation)
  Status
  affected
  Constraints
  -
Vendor Microsoft Product Windows Server 2012 R2 Default
n/a
- Version
  (Server Core installation)
  Status
  affected
  Constraints
  -
Vendor Microsoft Product Windows Server 2016 Default
n/a
- Version
  (Server Core installation)
  Status
  affected
  Constraints
  -

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor

Product

Default status

Versions

Microsoft

Windows 10

n/a

Version	Status	Constraints
32-bit Systems	affected	-
Version 1607 for 32-bit Systems	affected	-
Version 1607 for x64-based Systems	affected	-
Version 1703 for 32-bit Systems	affected	-
Version 1703 for x64-based Systems	affected	-
Version 1709 for 32-bit Systems	affected	-
Version 1709 for x64-based Systems	affected	-
x64-based Systems	affected	-

Microsoft

Windows 10 Servers

n/a

Version	Status	Constraints
version 1709 (Server Core Installation)	affected	-

Microsoft

Windows 7

n/a

Version	Status	Constraints
32-bit Systems Service Pack 1	affected	-
x64-based Systems Service Pack 1	affected	-

Microsoft

Windows 8.1

n/a

Version	Status	Constraints
32-bit systems	affected	-
x64-based systems	affected	-

Microsoft

Windows RT 8.1

n/a

Version	Status	Constraints
Windows RT 8.1	affected	-

Microsoft

Windows Server 2008

n/a

Version	Status	Constraints
32-bit Systems Service Pack 2	affected	-
32-bit Systems Service Pack 2 (Server Core installation)	affected	-
Itanium-Based Systems Service Pack 2	affected	-
x64-based Systems Service Pack 2	affected	-
x64-based Systems Service Pack 2 (Server Core installation)	affected	-

Microsoft

Windows Server 2008 R2

n/a

Version	Status	Constraints
Itanium-Based Systems Service Pack 1	affected	-
x64-based Systems Service Pack 1	affected	-
x64-based Systems Service Pack 1 (Server Core installation)	affected	-

Microsoft

Windows Server 2012

n/a

Version	Status	Constraints
(Server Core installation)	affected	-

Microsoft

Windows Server 2012 R2

n/a

Version	Status	Constraints
(Server Core installation)	affected	-

Microsoft

Windows Server 2016

n/a

Version	Status	Constraints
(Server Core installation)	affected	-

Remediation

No remediation recorded yet.

Metrics

12.57% 0.12568

Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 1, 2026.

EPSS probability 0.12568

Score over time

2021–2026

EPSS v1
EPSS v2
EPSS v3
EPSS v4
EPSS v5

Percentile over time

EPSS v1
EPSS v2
EPSS v3
EPSS v4
EPSS v5

Table of values (36 key points)

Flat stretches are collapsed; showing up to 120 newest points.

Date	Score	Percentile	Model
Oct 1, 2026	12.57% (0.12568)	96.12th	v5 (v2026.06.15)
Jun 15, 2026	11.80% (0.11796)	95.53th	v5 (v2026.06.15)
Jun 13, 2026	22.39% (0.22394)	95.97th	v4 (v2025.03.14)
Apr 2, 2026	20.23% (0.20231)	95.48th	v4 (v2025.03.14)
Mar 16, 2026	15.95% (0.15947)	94.66th	v4 (v2025.03.14)
Jan 25, 2026	17.88% (0.17881)	94.95th	v4 (v2025.03.14)
Dec 27, 2025	22.52% (0.22515)	95.67th	v4 (v2025.03.14)
Nov 29, 2025	18.30% (0.18305)	94.95th	v4 (v2025.03.14)
Nov 21, 2025	14.34% (0.14337)	94.14th	v4 (v2025.03.14)
Nov 18, 2025	17.58% (0.17576)	94.59th	v4 (v2025.03.14)
Jul 5, 2025	14.34% (0.14337)	94.08th	v4 (v2025.03.14)
Mar 30, 2025	17.95% (0.17949)	94.63th	v4 (v2025.03.14)
Mar 29, 2025	34.08% (0.34081)	95.29th	v4 (v2025.03.14)
Mar 19, 2025	17.95% (0.17949)	94.41th	v4 (v2025.03.14)
Mar 17, 2025	12.32% (0.12317)	93.32th	v4 (v2025.03.14)
Dec 12, 2024	0.43% (0.00425)	75.14th	v3 (v2023.03.01)
Feb 28, 2024	0.43% (0.00425)	73.72th	v3 (v2023.03.01)
Jan 10, 2024	0.51% (0.00506)	73.96th	v3 (v2023.03.01)
Dec 1, 2023	0.48% (0.00479)	73.06th	v3 (v2023.03.01)
Aug 8, 2023	0.60% (0.00600)	75.66th	v3 (v2023.03.01)
Jul 8, 2023	0.61% (0.00610)	75.75th	v3 (v2023.03.01)
Jul 4, 2023	0.46% (0.00460)	71.90th	v3 (v2023.03.01)
May 16, 2023	0.48% (0.00476)	72.16th	v3 (v2023.03.01)
May 8, 2023	0.67% (0.00674)	76.81th	v3 (v2023.03.01)
Mar 27, 2023	0.89% (0.00891)	80.19th	v3 (v2023.03.01)
Mar 7, 2023	1.26% (0.01260)	83.45th	v3 (v2023.03.01)
Mar 6, 2023	6.42% (0.06416)	91.03th	v2 (v2022.01.01)
Oct 31, 2022	6.42% (0.06416)	90.76th	v2 (v2022.01.01)
May 23, 2022	5.85% (0.05853)	89.68th	v2 (v2022.01.01)
Apr 16, 2022	5.27% (0.05274)	88.85th	v2 (v2022.01.01)
Apr 1, 2022	4.79% (0.04794)	88.19th	v2 (v2022.01.01)
Feb 4, 2022	4.79% (0.04794)	74.58th	v2 (v2022.01.01)
Feb 3, 2022	10.69% (0.10686)	87.85th	v1
Jan 6, 2022	10.69% (0.10686)	87.71th	v1
Sep 1, 2021	10.69% (0.10686)	95.19th	v1
Apr 14, 2021	10.69% (0.10686)	0.00th	v1

Weaknesses (0)

No CWE recorded.

References (3)

http://www.securityfocus.com/bid/104617
vdb-entryx_refsource_BIDThird Party AdvisoryVDB Entry
http://www.securitytracker.com/id/1041262
vdb-entryx_refsource_SECTRACKThird Party AdvisoryVDB Entry
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2018-8304
x_refsource_CONFIRMPatchVendor Advisory

Link	Providers	Tags
http://www.securityfocus.com/bid/104617		vdb-entryx_refsource_BIDThird Party AdvisoryVDB Entry
http://www.securitytracker.com/id/1041262		vdb-entryx_refsource_SECTRACKThird Party AdvisoryVDB Entry
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2018-8304		x_refsource_CONFIRMPatchVendor Advisory

Change history (0)

No recorded changes yet.

Sources

CVE.org / MITRE

Status PUBLISHED

Assigner microsoft

Published Jul 11, 2018

Updated Aug 5, 2024

Reserved Mar 14, 2018

Link CVE-2018-8304

CISA Vulnrichment

Updated n/a

NVD

Status Modified

Modified Jun 17, 2026

Link CVE-2018-8304

Red Hat

Severity n/a

Public date n/a

Links CVE-2018-8304