CVE-2026-21513

HIGHNVD 8.89.0▲Trending — 5 sources updated this weekExploited in the wild

8.8

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

CVSS v3: 8.8
EG Score: 9.0(high)
EPSS: 96.3%
KEV: ⚠ Exploited

Published

February 10, 2026

Last Modified

March 30, 2026

References (4)

secure@microsofthttps://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21513
af854a3a-2127-422b-91ae-364da2661108https://www.vicarius.io/vsociety/posts/cve-2026-21513-detection-script-security-feature-bypass-vulnerability-in-mshtml-framework
af854a3a-2127-422b-91ae-364da2661108https://www.vicarius.io/vsociety/posts/cve-2026-21513-mitigation-script-security-feature-bypass-vulnerability-in-mshtml-framework
134c704f-9b21-4f2e-91b3-4a467353bcc0https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-21513

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

CWE-693Protection Mechanism Failure

All Vendor Advisories

(1)

Every vendor that published an advisory referencing this CVE — pulled from our cve_vendor_advisories aggregation. Click any row for the vendor's original advisory page.

Microsoft MSRCCVE-2026-215132026-02-10
MSHTML Framework Security Feature Bypass Vulnerability

Data Freshness Timeline

(refreshed 14× in last 7d / 14× in last 30d)

Every time one of our enrichment pipelines (NVD, MITRE cvelistV5, EPSS, CISA KEV, GHSA, OSV, vendor advisories) ran against this CVE. Most recent first.

2026-05-31 23:19 UTCEG score recompute▲ 0.20
2026-05-31 23:19 UTCVendor advisory
2026-05-31 23:19 UTCGHSA enrichment
2026-05-31 22:30 UTCepss_batch
2026-05-31 22:30 UTCepss_batch
2026-05-31 00:16 UTCepss_batch
2026-05-31 00:16 UTCepss_batch
2026-05-31 00:16 UTCepss_batch
2026-05-29 22:20 UTCkev_newly_listed
2026-05-29 14:11 UTCEG score recompute
2026-05-29 14:11 UTCVendor advisory
2026-05-29 14:11 UTCGHSA enrichment
2026-05-29 13:44 UTCepss_batch
2026-05-29 13:44 UTCepss_batch

Frequently asked(6)

What is CVE-2026-21513?

CVE-2026-21513 is a high vulnerability published on February 10, 2026. Protection mechanism failure in MSHTML Framework allows an unauthorized attacker to bypass a security feature over a network.

When was CVE-2026-21513 disclosed?

CVE-2026-21513 was first published in the National Vulnerability Database on February 10, 2026, with the most recent update on March 30, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.

Is CVE-2026-21513 actively exploited?

Yes. CISA added CVE-2026-21513 to the Known Exploited Vulnerabilities catalog on February 10, 2026, affecting Microsoft Windows. KEV listing indicates confirmed exploitation in the wild; this CVE warrants immediate patching attention.

What is the CVSS score of CVE-2026-21513?

CVE-2026-21513 has a CVSS v3 base score of 8.8 (NVD). EchelonGraph synthesises NVD + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 9.0.

Which products are affected by CVE-2026-21513?

CVE-2026-21513 affects Microsoft Windows. The full affected-products list, including version ranges and fixed versions, is shown in the Affected Packages section of this page.

How do I remediate CVE-2026-21513?

Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-21513, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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CVE-2026-21513

Published

Last Modified

References (4)

Weakness Classification(1)

All Vendor Advisories

Data Freshness Timeline

Frequently asked(6)

Dependency Blast Radius

Is Your Infrastructure Affected by CVE-2026-21513?

Same vendor

Same CWE

CVE-2026-21513

📅 Published

🔄 Last Modified

🔗 References (4)

Weakness Classification(1)

All Vendor Advisories

Data Freshness Timeline

❓ Frequently asked(6)

Dependency Blast Radius

Is Your Infrastructure Affected by CVE-2026-21513?

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References (4)

Frequently asked(6)

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