Windows PostScript Printer Driver: Heap-based buffer overflow
Summary
The Microsoft PostScript Printer Driver in Windows contains a heap-based buffer overflow (CWE-122). A local user or malware already running on the system can exploit it to gain higher privileges. According to the CVSS vector, user interaction is required and the attacker needs a local foothold first; the CNA record lists many Windows 10, 11 and Server versions as affected, while the CPE data lists only Windows 10 1607.
Affected
- Windows 10 Version 1607 (builds 10.0.14393.0 to below 10.0.14393.9612)
- Windows 10 Version 1809 (builds 10.0.17763.0 to below 10.0.17763.9376)
- Windows 10 Version 21H2 (builds 10.0.19044.0 to below 10.0.19044.7807)
- Windows 10 Version 22H2 (builds 10.0.19045.0 to below 10.0.19045.7807)
- Windows 11 Versions 23H2, 24H2, 25H2, 26H1 and 26H2 (see the MSRC advisory for exact builds)
- Windows Server 2012 and 2012 R2 including Server Core
- Windows Server 2016 (builds below 10.0.14393.9612)
Fixed in
- Windows 10 1607 / Server 2016: 10.0.14393.9612
- Windows 10 1809: 10.0.17763.9376
- Windows 10 21H2: 10.0.19044.7807
- Windows 10 22H2: 10.0.19045.7807
- Windows 11 23H2: 10.0.22631.7652
- Windows 11 24H2, 25H2, 26H2: 10.0.26100.9711 / 10.0.26200.9711 / 10.0.26300.9711
- Windows 11 26H1: 10.0.28000.3231
- Windows Server 2012: 6.2.9200.26434
- Windows Server 2012 R2: 6.3.9600.23470
Verify these builds on the MSRC advisory before rollout.
Workaround
- Uninstall or disable the PostScript printer driver if it is not required.
Exploitation
- CISA SSVC: exploitation none, automatable no, technical impact total.
- Not listed in the CISA KEV catalog in the sources reviewed.
- EPSS score 0.00427 (very low).
- No public proof of concept found.
Our recommendation
- Check the MSRC advisory for the exact fixed builds.
- Inventory Windows 10 1607, Windows Server 2012, 2012 R2 and 2016 systems.
- Remove the PostScript printer driver where it is not needed.
- Install the cumulative update on the remaining systems in the next patch cycle.
- Treat Windows 10 1607 as an upgrade item and confirm its support status on Microsoft's lifecycle page.
- Monitor endpoints for unusual privilege escalation activity.
Information from Microsoft (Patch Tuesday October 2026)
- Severity (Microsoft)
- Important
- Impact
- Elevation of privilege – Microsoft PostScript Printer Driver
- Status on Patch Tuesday
- Neither exploited nor publicly disclosed
- Exploitability assessment
- Exploitation less likely
- Product family
- Windows, Windows ESU (Extended Security Updates)
- Updates (KB)
- KB5126835, KB5126836, KB5126868, KB5126651, KB5126657, KB5127648
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- MSRC Security Update Guide: CVE-2026-70109 msrc.microsoft.com
- Vulners NVD record CVE-2026-70109 vulners.com
- Vulners CVE list record CVE-2026-70109 vulners.com
- Vulners MSCVE record MS:CVE-2026-70109 vulners.com
- OpenCVE CVE-2026-70109 app.opencve.io
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 2 Nov 2026, 04:16.
Original description (NVD)
Heap-based buffer overflow in Microsoft PostScript Printer Driver allows an unauthorized attacker to elevate privileges locally.
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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