CVE-2026-21513
MSHTML Framework Security Feature Bypass Vulnerability
Protection mechanism failure in MSHTML Framework allows an unauthorized attacker to bypass a security feature over a network.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- Required
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
MSHTML Framework Security Feature Bypass Vulnerability
Protection mechanism failure in MSHTML Framework allows an unauthorized attacker to bypass a security feature over a network.
- Record
CVE-2026-21513- CVSS 3.1
- 8.8 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C - Weakness
- CWE-693
- Updated
- 2026-11-02
EUVDEUVD-2026-7342
Protection mechanism failure in MSHTML Framework allows an unauthorized attacker to bypass a security feature over a network.
- Record
EUVD-2026-7342- CVSS 3.1
- 8.8 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-rqf6-jf48-p6rm
Protection mechanism failure in MSHTML Framework allows an unauthorized attacker to bypass a...
Protection mechanism failure in MSHTML Framework allows an unauthorized attacker to bypass a security feature over a network.
- Record
GHSA-rqf6-jf48-p6rm- CVSS 3.1
- 8.8 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H - Weakness
- CWE-693
- Updated
- 2026-11-02
CISA KEV No score
Microsoft MSHTML Framework Protection Mechanism Failure Vulnerability
Microsoft MSHTML Framework contains a protection mechanism failure vulnerability that could allow an unauthorized attacker to bypass a security feature over a network.
- Record
CVE-2026-21513- Weakness
- CWE-693
- Updated
- 2026-11-02
NVD
Protection mechanism failure in MSHTML Framework allows an unauthorized attacker to bypass a security feature over a network.
- Record
CVE-2026-21513- CVSS 3.1
- 8.8 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H - Weakness
- CWE-693
- Updated
- 2026-11-02
Affected products
- microsoft windows
- microsoft windows 10 version 1607
- microsoft windows 10 version 1809
- microsoft windows 10 version 21h2
- microsoft windows 10 version 22h2
- microsoft windows 11 version 22h3
- microsoft windows 11 version 23h2
- microsoft windows 11 version 24h2
- microsoft windows 11 version 25h2
- microsoft windows 11 version 26h1
- microsoft windows server 2012
- microsoft windows server 2012 (server core installation)
Show 18 moreShow less
- microsoft windows server 2012 r2
- microsoft windows server 2012 r2 (server core installation)
- microsoft windows server 2016
- microsoft windows server 2016 (server core installation)
- microsoft windows server 2019
- microsoft windows server 2019 (server core installation)
- microsoft windows server 2022
- microsoft windows server 2022, 23h2 edition (server core installation)
- microsoft windows server 2025
- microsoft windows server 2025 (server core installation)
- microsoft windows 10 1607
- microsoft windows 10 1809
- microsoft windows 10 21h2
- microsoft windows 10 22h2
- microsoft windows 11 23h2
- microsoft windows 11 24h2
- microsoft windows 11 25h2
- microsoft windows server 2022 23h2
History
| Recorded | Changed | Sources |
|---|---|---|
| exploitation | ||
| first indexed | CVE List, EUVD, GitHub Advisories, CISA KEV, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-21513 is a high vulnerability (CVSS 8.8) in Microsoft Windows, published February 10, 2026. CISA lists it as known to be exploited, since February 10, 2026. EUVD reports exploitation since February 10, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 15.9%, the 96th percentile. No source names a fixed version.
References
msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21513
cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-21513
vicarius.io/vsociety/posts/cve-2026-21513-detection-script-security-feature-bypass-vulnerability-in-mshtml-framework
nvd.nist.gov/vuln/detail/CVE-2026-21513
github.com/advisories/GHSA-rqf6-jf48-p6rm