CVE-2020-0938 Microsoft Windows Adobe Font Manager Library Remote Code Execution Vulnerability
Microsoft Windows Adobe Font Manager Library contains an unspecified vulnerability when handling specially crafted multi-master fonts (Adobe Type 1 PostScript format) that allows for remote code execution for all systems except Windows 10. For systems running Windows 10, an attacker who successfully exploited the vulnerability could execute code in an AppContainer sandbox context with limited privileges and capabilities.
From the CISA KEV catalogue version 2026.11.06, with Cybergen analysis. Updated 6 Nov 2026.
Should You Worry?
- CISA confirmed exploitation in the wild and added it to the Known Exploited Vulnerabilities catalogue on 3 Nov 2021.
- Rated High severity (CVSS 7.8, scored by CISA).
- It has been in the catalogue for 1,829 days. Systems still unpatched now have almost certainly been scanned for it.
What It Is
A remote code execution vulnerability exists in Microsoft Windows when the Windows Adobe Type Manager Library improperly handles a specially-crafted multi-master font - Adobe Type 1 PostScript format.For all systems except Windows 10, an attacker who successfully exploited the vulnerability could execute code remotely, aka 'Adobe Font Manager Library Remote Code Execution Vulnerability'. This CVE ID is unique from CVE-2020-1020.
Affected Versions
| Product | Versions |
|---|---|
| Microsoft Windows | 10 Version 1803 for 32-bit Systems 10 Version 1803 for x64-based Systems 10 Version 1803 for ARM64-based Systems 10 Version 1809 for 32-bit Systems 10 Version 1809 for x64-based Systems 10 Version 1809 for ARM64-based Systems |
| Microsoft Windows Server | version 1803 (Core Installation) 2019 2019 (Core installation) 2016 2016 (Core installation) 2008 for 32-bit Systems Service Pack 2 |
| Microsoft Windows 10 Version 1909 for 32-bit Systems | unspecified |
| Microsoft Windows 10 Version 1909 for x64-based Systems | unspecified |
| Microsoft Windows 10 Version 1909 for ARM64-based Systems | unspecified |
| Microsoft Windows Server, version 1909 (Server Core installation) | unspecified |
From the public CVE record, as supplied by the vendor. Always confirm against the vendor advisory.
What To Do Now
- 1
Find it
Search your asset inventory and external attack surface for Microsoft Windows. Include cloud images, appliances and anything a supplier runs for you.
Attack Surface Management - 2
- 3
Hunt for compromise
If an affected system was reachable before you patched, assume it may have been hit. Check logs, new accounts, web shells and outbound connections from the date of exposure.
Incident Response - 4
Prove it is fixed
Rescan or test the system after patching. Upgrades that fail silently and forgotten secondary instances are common.
Penetration Testing
Vendor Advisories
The Compliance Clock
General guidance, not legal advice. Your obligations depend on your sector, scope and jurisdiction.
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