CVE-2025-26634Network attack vector

Privilege escalation via Core Messaging heap overflow

Published Mar 11, 2025 · Updated Feb 26, 2026

A heap-based buffer overflow in Microsoft Windows Core Messaging allows remote authenticated users to elevate privileges over a network. Microsoft has not published the input, code path, or incorrect memory operation responsible for overwriting the heap allocation. Exploitation requires existing low-privileged access and favorable heap conditions, and successful exploitation grants elevated control of the affected system.

CVSS severity7.5
High
EPSS probability0.66%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

A heap-based buffer overflow in Microsoft Windows Core Messaging allows remote authenticated users to elevate privileges over a network. Microsoft has not published the input, code path, or incorrect memory operation responsible for overwriting the heap allocation. Exploitation requires existing low-privileged access and favorable heap conditions, and successful exploitation grants elevated control of the affected system.

The record

CVE
CVE-2025-26634
Published
Mar 11, 2025
Updated
Feb 26, 2026
Vendor
Microsoft
Product
Windows 10 Version 1507
Classifications
CWE-122, T1068
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 11, 2025CVE publishedPublication date reported by the CVE source.
  2. Feb 26, 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 <10.0.10240.20915

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Microsoft · Windows 10 Version 1507version=10.0.10240.0 <10.0.10240.20915
Microsoft · Windows Server 2019version=10.0.17763.0 <10.0.17763.6893
Microsoft · Windows Server 2025 (Server Core installation)version=10.0.26100.0 <10.0.26100.3194
Microsoft · Windows Server 2016 (Server Core installation)version=10.0.14393.0 <10.0.14393.7785
Microsoft · Windows 11, version 24H2version=10.0.26100.0 <10.0.26100.3194
Microsoft · Windows 10 Version 21H2version=10.0.19044.0 <10.0.19044.5487
Microsoft · Windows Server 2022, 23H2 Edition (Server Core installation)version=10.0.25398.0 <10.0.25398.1425
Microsoft · Windows Server 2016version=10.0.14393.0 <10.0.14393.7785
Microsoft · Windows 11 Version 22H3version=10.0.22631.0 <10.0.22631.4890
Microsoft · Windows 10 Version 22H2version=10.0.19045.0 <10.0.19045.5487
Microsoft · Windows Server 2019 (Server Core installation)version=10.0.17763.0 <10.0.17763.6893
Microsoft · Windows 11 Version 23H2version=10.0.22631.0 <10.0.22631.4890
Microsoft · Windows 11, version 22H2version=10.0.22621.0 <10.0.22621.4890
Microsoft · Windows 10 Version 1607version=10.0.14393.0 <10.0.14393.7785
Microsoft · Windows Server 2022version=10.0.20348.0 <10.0.20348.3207
Microsoft · Windows Server 2025version=10.0.26100.0 <10.0.26100.3194
Microsoft · Windows 10 Version 1809version=10.0.17763.0 <10.0.17763.6893

Published CVSS scores

7.5Microsoft CorporationCVSS:3.1/AV:N/AC:H/PR:L/UI:N/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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-122Heap-based Buffer Overflow
T1068Exploitation for Privilege Escalation

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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