Is It On KEV?

Microsoft Windows

YES - ON THE CISA KEV LIST
CVE-2021-34527

Microsoft Windows Print Spooler Remote Code Execution Vulnerability

CISA catalog due date2022-05-03
overdue since 2022-05-03
EPSS exploit probability (next 30 days)99.8% · 100percentile
From CVE publication to KEV listing124 days (2021-07-02 → 2021-11-03)
Remediation window (KEV listing to due date)181 days
Days on the KEV list1834 days
Date added to KEV2021-11-03
Known ransomware campaign useKnown
VendorMicrosoft
ProductWindows
Weaknesses (CWE)CWE-269

Microsoft: 391 entries (22.0% of all KEV entries are from this vendor); 41 added in 2026.

BOD 26-04 note: this is the date printed in the CISA catalog. A federal agency's actual deadline is set by its SSVC tier - Act (3 days), Attend (14 days), Track (60 days), or the next scheduled upgrade - counted from the KEV listing date or the date the vulnerability is identified in its environment, whichever comes first. Use the tier helper on each CVE page for your own window.

Your BOD 26-04 window (SSVC tier helper)

Your remediation window ends:

Description

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.

Required action (CISA)

Apply updates per vendor instructions.

Notes

Reference CISA's ED 21-04 (https://www.cisa.gov/news-events/directives/ed-21-04-mitigate-windows-print-spooler-service-vulnerability) for further guidance and requirements. Note: The due date for addressing this vulnerability aligns with the requirements outlined in ED 21-04. https://nvd.nist.gov/vuln/detail/CVE-2021-34527

References

Other KEV entries for this vendor: Microsoft

Microsoft - Vendors with KEV entries

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