CVE-2025-26666

Local code execution via media heap overflow

Published Apr 8, 2025 · Updated Aug 10, 2026

Heap-based buffer overflow in Windows Media on affected Windows releases allows local authenticated users to execute arbitrary code. Microsoft identifies Windows Media as the locus but has not disclosed the parser, media format, or unchecked allocation or copy operation that corrupts the heap. Exploitation requires low local privileges and no user interaction, and successful code execution can compromise data and interrupt the affected host.

CVSS severity7.8
High
EPSS probability0.63%
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

Heap-based buffer overflow in Windows Media on affected Windows releases allows local authenticated users to execute arbitrary code. Microsoft identifies Windows Media as the locus but has not disclosed the parser, media format, or unchecked allocation or copy operation that corrupts the heap. Exploitation requires low local privileges and no user interaction, and successful code execution can compromise data and interrupt the affected host.

The record

CVE
CVE-2025-26666
Published
Apr 8, 2025
Updated
Aug 10, 2026
Vendor
Microsoft
Product
Windows Server 2019
Classifications
CWE-122
Attack vector
local
Privileges
authenticated

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=10.0.17763.0 <10.0.17763.7136

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

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 11, version 24H2version=10.0.26100.0 <10.0.26100.3775
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 11 Version 22H3version=10.0.22631.0 <10.0.22631.5189
Microsoft · Windows 10 Version 22H2version=10.0.19045.0 <10.0.19045.5737
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 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

Published CVSS scores

7.8Microsoft CorporationCVSS:3.1/AV:L/AC:L/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)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-122Heap-based Buffer Overflow

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