CVE-2025-53805 — HTTP.sys Denial of Service Vulnerability

Executive Summary

Out-of-bounds read in Windows Internet Information Services allows an unauthorized attacker to deny service over a network.

Overview

7.5

CVSS HIGH

Important

MS Severity

Not Exploited

MS Exploit Status

Exploitation Unlikely

MS Exploit Likelihood

Category Denial of Service

Weakness CWE-125: Out-of-bounds Read

Released Sep 9 2025

Last Updated Sep 9 2025

Publicly Disclosed No

CISA KEV Not Listed

Known Exploits None Known

EPSS Score 0.01345 — 0.68479 percentile

NVD CVSS 7.5 HIGH — matches MSRC

CVSS Vector

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

ATTACK VECTOR

Network

ATTACK COMPLEXITY

Low

PRIVILEGES REQUIRED

None

USER INTERACTION

None

SCOPE

Unchanged

CONFIDENTIALITY

None

INTEGRITY

None

AVAILABILITY

High

EXPLOIT CODE MATURITY

Unproven

REMEDIATION LEVEL

Official Fix

REPORT CONFIDENCE

Confirmed

Temporal Score: 6.5

EPSS Score

0.01345

probability of exploitation in the next 30 days

0.68479 percentile - updated 2026-07-25

View on FIRST.org

Affected Products

5 affected products

Product	KB Article	Severity	Impact	Restart Required
Windows 11 Version 22H2 for ARM64-based Systems	`5065431 (Security Update)`	Important	Denial of Service	Yes
Windows 11 Version 22H2 for x64-based Systems	`5065431 (Security Update)`	Important	Denial of Service	Yes
Windows 11 Version 23H2 for ARM64-based Systems	`5065431 (Security Update)`	Important	Denial of Service	Yes
Windows 11 Version 23H2 for x64-based Systems	`5065431 (Security Update)`	Important	Denial of Service	Yes
Windows 11 Version 24H2 for ARM64-based Systems 5065426 (Security Update) 5065474 (SecurityHotpatchUpdate) Important Denial of Service 5063878 5064010 Base: 7.5 Temporal: 6.5 Vector: 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 10.0.26100.6584 10.0.26100.6508 Yes None Windows 11 Version 24H2 for x64-based Systems 5065426 (Security Update) 5065474 (SecurityHotpatchUpdate) Important Denial of Service 5063878 5064010 Base: 7.5 Temporal: 6.5 Vector: 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 10.0.26100.6584 10.0.26100.6508 Yes None Windows Server 2022 5065432 (Security Update) 5065306 (SecurityHotpatchUpdate) Important Denial of Service 5063880 5063812 Base: 7.5 Temporal: 6.5 Vector: 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 10.0.20348.4171 10.0.20348.4106 Yes None Windows Server 2022 (Server Core installation) 5065432 (Security Update) 5065306 (SecurityHotpatchUpdate) Important Denial of Service 5063880 5063812 Base: 7.5 Temporal: 6.5 Vector: 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 10.0.20348.4171 10.0.20348.4106 Yes None Windows Server 2022, 23H2 Edition (Server Core installation)	`5065425 (Security Update)`	Important	Denial of Service	Yes

Patches

2 patches

Article	Type	Restart
`5065431`	Security Update	Yes
`5065425`	Security Update	Yes

Known Exploits

No known exploits have been linked for this CVE yet. When available, exploit references will be sourced from public repositories and may be unverified, incomplete, or non-functional. Always review code carefully before use in any environment.

Acknowledgments

Rutuja Shirali with Microsoft
Yesayi Hovnanyan with Microsoft
Matthew Cox with Microsoft

References

MSRC Advisory MITRE NVD