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PatchSiren cyber security CVE debrief

CVE-2016-7255 Microsoft CVE debrief

CVE-2016-7255 is a Microsoft Win32k privilege escalation vulnerability that CISA has included in its Known Exploited Vulnerabilities catalog. That KEV listing means defenders should treat it as an actively exploited issue and prioritize remediation on affected Microsoft systems.

Vendor
Microsoft
Product
Win32k
CVSS
Unknown
CISA KEV
Listed
Original CVE published
2021-11-03
Original CVE updated
2021-11-03
Advisory published
2021-11-03
Advisory updated
2021-11-03

Who should care

Windows administrators, endpoint security teams, vulnerability management teams, and incident responders responsible for Microsoft-managed systems should prioritize this CVE, especially in environments where patching is centralized and delays can leave endpoints exposed.

Technical summary

The supplied sources identify this issue as a Microsoft Win32k privilege escalation vulnerability. CISA’s KEV catalog entry indicates it is known to be exploited in the wild. The practical defensive implication is that affected Microsoft systems should be updated per vendor guidance and then verified for successful remediation.

Defensive priority

High. CISA has placed this CVE in the Known Exploited Vulnerabilities catalog, which is a strong signal to prioritize patching and validation ahead of routine maintenance work.

Recommended defensive actions

  • Apply vendor-recommended updates for affected Microsoft systems as soon as possible.
  • Verify remediation across endpoints and servers that use the affected Microsoft component.
  • Use the CISA KEV catalog entry as a trigger to prioritize exposure reduction and patch compliance checks.
  • Confirm that asset inventories and patch reporting cover all Windows systems in scope.

Evidence notes

The CVE record and NVD detail page identify the issue as Microsoft Win32k privilege escalation vulnerability. The CISA KEV source marks it as a known exploited vulnerability and lists the required action as applying updates per vendor instructions. The supplied timeline shows the CVE and KEV entry dates as 2021-11-03, with a KEV due date of 2022-05-03.

Official resources

The supplied timeline shows CVE publication and modification on 2021-11-03. CISA added the entry to KEV on 2021-11-03 and set a due date of 2022-05-03.