Microsoft XPS Document Converter: Heap buffer overflow enables remote code execution
Summary
A heap-based buffer overflow in the Microsoft XPS Document Converter component of Windows allows an unauthenticated attacker to execute code over the network. The attack requires user interaction, most likely opening or printing a crafted document. The CVSS base score is 8.8 (High).
Affected
- Windows 10 Version 1607 (10.0.14393.0 to before 10.0.14393.9688)
- Windows 10 Version 1809 (10.0.17763.0 to before 10.0.17763.9487)
- Windows 10 Version 21H2 (10.0.19044.0 to before 10.0.19044.7846)
- Windows 10 Version 22H2 (10.0.19045.0 to before 10.0.19045.7846)
- Windows 11 Version 23H2 (10.0.22631.0 to before 10.0.22631.7711)
- Windows 11 Version 24H2 (10.0.26100.0 to before 10.0.26100.9974)
- Windows 11 Version 25H2 (10.0.26200.0 to before 10.0.26200.9974)
- Windows 11 Version 26H1 (10.0.28000.0 to before 10.0.28000.3501)
- Windows 11 Version 26H2 (10.0.26300.0 to before 10.0.26300.9974)
- Windows Server 2016, including Server Core (10.0.14393.0 to before 10.0.14393.9688)
- Windows Server 2019, including Server Core (10.0.17763.0 to before 10.0.17763.9487)
- Windows Server 2022 (10.0.20348.0 to before 10.0.20348.5870)
Fixed in
- Install the Microsoft security update that brings the builds listed above to or beyond the stated fixed versions. The update-specific KB number is unconfirmed.
- Verify the exact fixed build for each Windows version in the MSRC advisory.
Workaround
Unknown.
Exploitation
- No known exploitation in the wild at publication.
- Not listed in the CISA KEV catalogue at publication.
- The CVSS exploit code maturity is Unproven (E:U), indicating no public exploit code at publication.
Our recommendation
- Deploy the Microsoft Windows security update for November 2026 to all affected clients and servers, starting with systems that open external documents.
- Check for Windows 10 devices, including versions 1607 and 1809, that are out of vendor support or lagging on updates.
- Restrict opening untrusted XPS and other documents from email or the web, and monitor the MSRC advisory and CISA KEV for changes.
Information from Microsoft (Patch Tuesday November 2026)
- Severity (Microsoft)
- Important
- Impact
- Remote code execution – Microsoft XPS Document Converter
- Status on Patch Tuesday
- Neither exploited nor publicly disclosed
- Exploitability assessment
- Exploitation less likely
- Product family
- Windows, Windows ESU (Extended Security Updates)
- Updates (KB)
- KB5131291, KB5131085, KB5131096, KB5131090, KB5131087, KB5132061
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- MSRC Security Update Guide: CVE-2026-122171 msrc.microsoft.com
- CVE.org record CVE-2026-122171 www.cve.org
- Strix AI: CVE-2026-122171 (third-party aggregator) www.strix.ai
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 10 Nov 2026, 21:26.
Original description (NVD)
Heap-based buffer overflow in Microsoft XPS Document Converter allows an unauthorized attacker to execute code 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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