Windows Codecs Library: Stack-based buffer overflow allows denial of service
Summary
A stack-based buffer overflow in the Microsoft Windows Codecs Library, which decodes media and image formats, can be triggered over the network. An unauthenticated attacker can crash or hang affected Windows systems, causing denial of service. Exploitation requires user interaction, such as opening or previewing a crafted file, and confidentiality and integrity are not affected.
Affected
- Windows 10 Version 1607 (10.0.14393.0 before 10.0.14393.9612)
- Windows 10 Version 1809 (10.0.17763.0 before 10.0.17763.9376)
- Windows 10 Version 21H2 (10.0.19044.0 before 10.0.19044.7807)
- Windows 10 Version 22H2 (10.0.19045.0 before 10.0.19045.7807, build number to be confirmed on MSRC)
- Windows 11 Versions 23H2, 24H2, 25H2, 26H1 and 26H2 (see MSRC for builds)
- Windows Server 2012 and 2012 R2 (including Server Core)
- Windows Server 2016 (10.0.14393.0 before 10.0.14393.9612)
Fixed in
- Windows 10 1607 and Server 2016: 10.0.14393.9612 (KB number unknown, confirm on MSRC)
- Windows 10 1809: 10.0.17763.9376 (KB5126651)
- Windows 10 21H2 and 22H2: 10.0.19044.7807 / 10.0.19045.7807 (KB5126657)
- Windows Server 2012 R2: KB5126836 (per Tenable)
- Windows Server 2012: 6.2.9200.26434
- Windows 11 and later: see MSRC for the fixed builds
Workaround
Unknown. No vendor-documented workaround is known. Patching is the stated remedy.
Exploitation
- No known exploitation in the wild and no public proof of concept at the time of research.
- Not listed in CISA KEV.
- CISA SSVC: exploitation none, not automatable, partial technical impact.
Our recommendation
- Inventory all Windows 10 1607, Server 2016 and other affected systems, especially old LTSB 2016 machines.
- Confirm the KB for Windows 10 1607 and Server 2016 on the MSRC advisory and deploy the October 2026 updates in the normal monthly cycle.
- Patch the Windows Codecs Library broadly, as a separate, more serious Codecs Library flaw (CVE-2026-58599) is also known.
- Re-check MSRC and CISA KEV for changes in exploitation status.
Information from Microsoft (Patch Tuesday October 2026)
- Severity (Microsoft)
- Important
- Impact
- Denial of service – Microsoft Windows Codecs Library
- Status on Patch Tuesday
- Neither exploited nor publicly disclosed
- Exploitability assessment
- Exploitation less likely
- Product family
- Windows, Windows ESU (Extended Security Updates)
- Updates (KB)
- KB5126651, KB5126655, KB5126657, KB5126646, KB5127648, KB5126653
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- Microsoft Security Update Guide (MSRC) msrc.microsoft.com
- Vulners CVE list record vulners.com
- Vulners NVD record vulners.com
- VulDB entry vuldb.com
- Strix CVE-2026-102199 (fixed builds) www.strix.ai
- Microsoft customer-risk document 2026 CVEs cdn-dynmedia-1.microsoft.com
- Tenable plugin 365468 www.tenable.com
Researched and written up in English and German by an AI (Claude by Anthropic) based on NVD, CISA, EPSS and the sources listed. The vendor information is authoritative. Researched on 5 Nov 2026, 11:34.
Original description (NVD)
Stack-based buffer overflow in Microsoft Windows Codecs Library allows an unauthorized attacker to deny service over a network.
NVD references (1)
Sources
The tracker combines official, freely usable data sources – updated continuously:
- NVD (NIST) – CVEs, rating (CVSS), affected products
- CISA KEV – vulnerabilities confirmed by CISA as actively exploited
- CISA Vulnrichment – CISA assessment (SSVC) in the official CVE record
- FIRST EPSS – probability of exploitation
- Microsoft MSRC – Patch Tuesday: vulnerabilities, severity, updates
- PoC-in-GitHub – public proof-of-concept repositories
- Metasploit (Rapid7) – modules of the Metasploit Framework
- Exploit-DB (OffSec) – archive of public exploits (links only)
- Patch days: official vendor pages (linked per vendor) (Vendor patch days)
This product uses data from the NVD API but is not endorsed or certified by the NVD. EPSS data © FIRST.org.
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