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Exploited vulnerability

CVE-2026-21510

TLP:CLEAR

Microsoft Windows Shell Protection Mechanism Failure Vulnerability

Microsoft Windows Shell contains a protection mechanism failure vulnerability that could allow an unauthorized attacker to bypass a security feature over a network.

Facts

  • Vendor: Microsoft
  • Product: Windows
  • CVSS: 8.8
  • EPSS (probability of exploitation within 30 days): 61.2 %
  • On CISA's Known Exploited Vulnerabilities list since: 10 February 2026
  • First known exploitation: 10 February 2026
  • CISA's deadline for US federal agencies: 3 March 2026
  • Weakness: CWE-693
  • First seen by Risk Letters: 10 February 2026

Members see which Nordic sectors the flaw hits, and what to do about it.

Get the full brief

Data: NVD (public domain), CISA KEV, FIRST EPSS, MITRE ATT&CK, AlienVault OTX. NVD

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