CVE-2026-21537

HIGHNVD 8.88.8—Trending — 4 sources updated this week

8.8

Improper control of generation of code ('code injection') in Microsoft Defender for Linux allows an unauthorized attacker to execute code over an adjacent network.

CVSS v3: 8.8
EG Score: 8.8(medium)
EPSS: 25.4%
KEV: Not listed

Published

February 10, 2026

Last Modified

February 11, 2026

References (1)

secure@microsofthttps://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21537

Weakness Classification(1)

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

CWE-94Improper Control of Generation of Code (Code Injection)

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-2026-215372026-02-10
Microsoft Defender for Endpoint Linux Extension Remote Code Execution Vulnerability

Data Freshness Timeline

(refreshed 7× in last 7d / 7× 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 22:30 UTCepss_batch
2026-05-31 22:30 UTCepss_batch
2026-05-29 14:10 UTCEG score recompute
2026-05-29 14:10 UTCVendor advisory
2026-05-29 14:10 UTCGHSA enrichment
2026-05-29 13:44 UTCepss_batch
2026-05-29 13:44 UTCepss_batch

Frequently asked(5)

What is CVE-2026-21537?

CVE-2026-21537 is a high vulnerability published on February 10, 2026. Improper control of generation of code ('code injection') in Microsoft Defender for Linux allows an unauthorized attacker to execute code over an adjacent network.

When was CVE-2026-21537 disclosed?

CVE-2026-21537 was first published in the National Vulnerability Database on February 10, 2026, with the most recent update on February 11, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.

Is CVE-2026-21537 actively exploited?

CVE-2026-21537 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 25.4% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.

What is the CVSS score of CVE-2026-21537?

CVE-2026-21537 has a CVSS v3 base score of 8.8 (NVD).

How do I remediate CVE-2026-21537?

Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-21537, 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-2026-21537

Published

Last Modified

References (1)

Weakness Classification(1)

All Vendor Advisories

Data Freshness Timeline

Frequently asked(5)

Dependency Blast Radius

Is Your Infrastructure Affected by CVE-2026-21537?

Same vendor

Same CWE

CVE-2026-21537

📅 Published

🔄 Last Modified

🔗 References (1)

Weakness Classification(1)

All Vendor Advisories

Data Freshness Timeline

❓ Frequently asked(5)

Dependency Blast Radius

Is Your Infrastructure Affected by CVE-2026-21537?

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Frequently asked(5)

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