CVE-2026-21510 · netVigilance record NV26-0024
Microsoft Windows Shell Protection Mechanism Failure
past due
What to do
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
CISA deadline 2026-03-03 · passed 6 months ago · applies to US federal civilian agencies; used elsewhere as a reference SLA
What happened
Microsoft Windows Shell contains a protection mechanism failure vulnerability that could allow an unauthorized attacker to bypass a security feature over a network.
Who is affected
Microsoft Windows. Affected version ranges are listed in the vendor advisory and the NVD entry linked under Sources.
Weakness class: CWE-693.
Timeline
- Added to CISA KEVExploitation in the wild confirmed by CISA
- CISA remediation deadlinepassed 6 months ago
Sources
- NVD entry for CVE-2026-21510 nvd.nist.gov/vuln/detail/CVE-2026-21510
- CISA Known Exploited Vulnerabilities catalog www.cisa.gov/known-exploited-vulnerabilities-catalog
- msrc.microsoft.com msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21510
- nvd.nist.gov nvd.nist.gov/vuln/detail/CVE-2026-21510