- High 8.8
- Known exploited (CISA KEV)
CVE-2026-21513
Protection mechanism failure in MSHTML Framework allows an unauthorized attacker to bypass a security feature over a network.
Scores
The facts
- Published
- 10 February 2026
- Last changed
- 17 June 2026
- NVD status
- Analyzed
- Severity
- High, CVSS 8.8 out of 10 (version 3.1)
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H - Weakness
- Affects
- microsoft windows 10 1607
- microsoft windows 10 1809
- microsoft windows 10 21h2
- microsoft windows 10 22h2
- microsoft windows 11 23h2
- Known exploited
- Yes. CISA added it to the Known Exploited Vulnerabilities catalogue on 10 February 2026.
- EPSS
- 15.9% chance of exploitation activity in the next 30 days (percentile 97).
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