CVE-2025-27477Network attack vector

Remote code execution via service heap overflow

Published Apr 8, 2025 · Updated Aug 10, 2026

Heap-based buffer overflow in Microsoft Windows Telephony Service allows remote attackers to execute code through network input. The service mishandles network input in a heap allocation, but Microsoft has not disclosed the affected parsing routine or field. Exploitation requires user interaction but no prior privileges and grants code execution in the service's security context.

CVSS severity8.8
High
EPSS probability1.55%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Heap-based buffer overflow in Microsoft Windows Telephony Service allows remote attackers to execute code through network input. The service mishandles network input in a heap allocation, but Microsoft has not disclosed the affected parsing routine or field. Exploitation requires user interaction but no prior privileges and grants code execution in the service's security context.

The record

CVE
CVE-2025-27477
Published
Apr 8, 2025
Updated
Aug 10, 2026
Vendor
Microsoft
Product
Windows 10 Version 1507
Classifications
CWE-787, CWE-122, T1210
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 8, 2025CVE publishedPublication date reported by the CVE source.
  2. Aug 10, 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 <10.0.10240.20978

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Microsoft · Windows 10 Version 1507version=10.0.10240.0 <10.0.10240.20978
Microsoft · Windows Server 2019version=10.0.17763.0 <10.0.17763.7136
Microsoft · Windows Server 2025 (Server Core installation)version=10.0.26100.0 <10.0.26100.3775
Microsoft · Windows Server 2016 (Server Core installation)version=10.0.14393.0 <10.0.14393.7969
Microsoft · Windows 11, version 24H2version=10.0.26100.0 <10.0.26100.3775
Microsoft · Windows Server 2012 (Server Core installation)version=6.2.9200.0 <6.2.9200.25423
Microsoft · Windows Server 2012version=6.2.9200.0 <6.2.9200.25423
Microsoft · Windows 10 Version 21H2version=10.0.19044.0 <10.0.19044.5737
Microsoft · Windows Server 2022, 23H2 Edition (Server Core installation)version=10.0.25398.0 <10.0.25398.1551
Microsoft · Windows Server 2016version=10.0.14393.0 <10.0.14393.7969
Microsoft · Windows 11 Version 22H3version=10.0.22631.0 <10.0.22631.5189
Microsoft · Windows Server 2008 R2 Service Pack 1version=6.1.7601.0 <6.1.7601.27670
Microsoft · Windows Server 2008 R2 Service Pack 1 (Server Core installation)version=6.1.7601.0 <6.1.7601.27670
Microsoft · Windows 10 Version 22H2version=10.0.19045.0 <10.0.19045.5737
Microsoft · Windows Server 2012 R2 (Server Core installation)version=6.3.9600.0 <6.3.9600.22523
Microsoft · Windows Server 2019 (Server Core installation)version=10.0.17763.0 <10.0.17763.7136
Microsoft · Windows 11 Version 23H2version=10.0.22631.0 <10.0.22631.5189
Microsoft · Windows 11, version 22H2version=10.0.22621.0 <10.0.22621.5189
Microsoft · Windows 10 Version 1607version=10.0.14393.0 <10.0.14393.7969
Microsoft · Windows Server 2008 Service Pack 2version=6.0.6003.0 <6.0.6003.23220
Microsoft · Windows Server 2022version=10.0.20348.0 <10.0.20348.3453
Microsoft · Windows Server 2025version=10.0.26100.0 <10.0.26100.3775
Microsoft · Windows 10 Version 1809version=10.0.17763.0 <10.0.17763.7136
Microsoft · Windows Server 2012 R2version=6.3.9600.0 <6.3.9600.22523
Microsoft · Windows Server 2008 Service Pack 2 (Server Core installation)version=6.0.6003.0 <6.0.6003.23220

Published CVSS scores

8.8MicrosoftCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

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-787Out-of-bounds Write
CWE-122Heap-based Buffer Overflow
T1210Exploitation of Remote Services

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

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Your stack

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