ACTIVELY EXPLOITED
CVE-2021-34527: Microsoft Windows Print Spooler Remote Code Execution Vulnerability
| Vendor | Microsoft |
|---|---|
| Product | Windows |
| Actively exploited | Yes |
| Added to CISA KEV | 3 Nov 2021 |
| CISA federal deadline | 3 May 2022 |
| Ransomware use | Known |
| Weakness (CWE) | CWE-269 |
Required action (CISA's text)
Apply updates per vendor instructions.
Description (NVD)
Microsoft Windows Print Spooler contains an unspecified vulnerability due to the Windows Print Spooler service improperly performing privileged file operations. Successful exploitation allows an attacker to perform remote code execution with SYSTEM privileges. The vulnerability is also known under the moniker of PrintNightmare.
SOURCES
Other Microsoft flaws
- patchtuesday:2026-11: Vulnerability in Microsoft
- CVE-2026-124194: Microsoft Office Outlook Missing User Interaction for Potentially Unsafe Action Vulnerability
- CVE-2026-96951: Microsoft Windows Command Injection Vulnerability
- CVE-2026-65660: Microsoft SharePoint Code Injection Vulnerability
- CVE-2026-85880: Microsoft Windows Heap-Based Buffer Overflow Vulnerability
Data from NVD, CISA KEV, FIRST EPSS and vendor advisories. Updated 10 Nov 2026.