peter bassill · operator
$ cve CVE-2026-21510 JSON

CVE-2026-21510 KEV

8.8
HIGH · CVSS 3.1 · EPSS 24.2% (pctl 98)

Patch first

On CISA KEV — known exploited in the wild, due 2026-03-03.

Description

Protection mechanism failure in Windows Shell allows an unauthorized attacker to bypass a security feature over a network.

Scoring

CVSS8.8 (HIGH, v3.1)
VectorCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS24.23% — more likely to be exploited than 98% of all CVEs
WeaknessCWE-693
On CISA KEVyes — remediate by 2026-03-03
Public exploitnone known
Published2026-02-10
Last modified2026-06-17

CISA KEV

NameMicrosoft Windows Shell Protection Mechanism Failure Vulnerability
Added2026-02-10
Due2026-03-03
Vendor / productMicrosoft / Windows
Ransomware usenone reported

Affected (13)

VendorProduct
microsoftwindows 10 1607
microsoftwindows 10 1809
microsoftwindows 10 21h2
microsoftwindows 10 22h2
microsoftwindows 11 23h2
microsoftwindows 11 24h2
microsoftwindows 11 25h2
microsoftwindows server 2012
microsoftwindows server 2016
microsoftwindows server 2019
microsoftwindows server 2022
microsoftwindows server 2022 23h2
microsoftwindows server 2025

References

→ the Explorer  ·  watch your stack  ·  NVD