CVE-2026-21510
Actively exploited. CVE-2026-21510 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2026-02-10) — exploitation has been observed in the wild, and US federal agencies are required to remediate it under BOD 22-01. Treat patching as urgent.
Microsoft Windows Shell contains a protection mechanism failure vulnerability that could allow an unauthorized attacker to bypass a security feature over a network.
CSIRTS triage
- What
- Windows Shell contains a protection mechanism failure vulnerability.
- Who is affected
- Users of Microsoft Windows Shell.
- Urgency
- Remediation is urgent due to active exploitation and critical severity.
- Action
- Apply the latest security updates for Microsoft Windows.
AI-assisted analysis generated from the source advisory — verify against the original.
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Exploitation outlook
- Exploitation confirmedAlready exploited in the wild (CISA KEV) — the prediction phase is over. Patch now. Riskier than 98% of all EPSS-scored CVEs.
Advisory coverage (1)
- criticalexploitedCVE-2026-21510: Microsoft Windows Shell Protection Mechanism Failure Vulnerabilitycisa-kev · 2026-02-10
External references
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