CVE-2025-55229Network attack vector

Network spoofing via improper certificate signature verification

Published Aug 21, 2025 · Updated Feb 13, 2026

Improper signature verification in Microsoft Windows Certificates allows remote attackers to perform spoofing over a network. Microsoft has not published the affected routine or the incorrect operation it performs while validating an untrusted certificate signature. Exploitation requires no credentials or user interaction and exposes limited confidential information without integrity or availability impact.

CVSS severity5.3
Medium
EPSS probability0.48%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Improper signature verification in Microsoft Windows Certificates allows remote attackers to perform spoofing over a network. Microsoft has not published the affected routine or the incorrect operation it performs while validating an untrusted certificate signature. Exploitation requires no credentials or user interaction and exposes limited confidential information without integrity or availability impact.

The record

CVE
CVE-2025-55229
Published
Aug 21, 2025
Updated
Feb 13, 2026
Vendor
Microsoft
Product
Windows 10 Version 1507
Classifications
CWE-347
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 21, 2025CVE publishedPublication date reported by the CVE source.
  2. Feb 13, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=10.0.10240.0 <10.0.10240.21014

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Microsoft · Windows 10 Version 1507version=10.0.10240.0 <10.0.10240.21014
Microsoft · Windows Server 2019version=10.0.17763.0 <10.0.17763.7314
Microsoft · Windows Server 2025 (Server Core installation)version=10.0.26100.0 <10.0.26100.4061
Microsoft · Windows Server 2016 (Server Core installation)version=10.0.14393.0 <10.0.14393.8066
Microsoft · Windows 11, version 24H2version=10.0.26100.0 <10.0.26100.4061
Microsoft · Windows 10 Version 21H2version=10.0.19044.0 <10.0.19044.5854
Microsoft · Windows Server 2022, 23H2 Edition (Server Core installation)version=10.0.25398.0 <10.0.25398.1611
Microsoft · Windows Server 2016version=10.0.14393.0 <10.0.14393.8066
Microsoft · Windows 11 Version 22H3version=10.0.22631.0 <10.0.22631.5335
Microsoft · Windows 10 Version 22H2version=10.0.19045.0 <10.0.19045.5854
Microsoft · Windows Server 2019 (Server Core installation)version=10.0.17763.0 <10.0.17763.7314
Microsoft · Windows 11 Version 23H2version=10.0.22631.0 <10.0.22631.5335
Microsoft · Windows 11, version 22H2version=10.0.22621.0 <10.0.22621.5335
Microsoft · Windows 10 Version 1607version=10.0.14393.0 <10.0.14393.8066
Microsoft · Windows Server 2022version=10.0.20348.0 <10.0.20348.3692
Microsoft · Windows Server 2025version=10.0.26100.0 <10.0.26100.4061
Microsoft · Windows 10 Version 1809version=10.0.17763.0 <10.0.17763.7314

Published CVSS scores

5.3MicrosoftCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-347Improper Verification of Cryptographic Signature

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo