CVE-2026-21249

LOWNVD 3.33.3—Trending — 4 sources updated this week

3.3

External control of file name or path in Windows NTLM allows an unauthorized attacker to perform spoofing locally.

CVSS v3: 3.3
EG Score: 3.3(medium)
EPSS: 20.3%
KEV: Not listed

Published

February 10, 2026

Last Modified

February 11, 2026

References (1)

secure@microsofthttps://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21249

Weakness Classification(1)

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

CWE-73

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-2026-212492026-02-10
Windows NTLM Spoofing Vulnerability

Data Freshness Timeline

(refreshed 10× in last 7d / 10× 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
2026-05-31 00:16 UTCepss_batch
2026-05-31 00:16 UTCepss_batch
2026-05-31 00:16 UTCepss_batch
2026-05-29 14:13 UTCEG score recompute
2026-05-29 14:13 UTCVendor advisory
2026-05-29 14:13 UTCGHSA enrichment
2026-05-29 13:44 UTCepss_batch
2026-05-29 13:44 UTCepss_batch

Frequently asked(5)

What is CVE-2026-21249?

CVE-2026-21249 is a low vulnerability published on February 10, 2026. External control of file name or path in Windows NTLM allows an unauthorized attacker to perform spoofing locally.

When was CVE-2026-21249 disclosed?

CVE-2026-21249 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-2026-21249 actively exploited?

CVE-2026-21249 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 20.3% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.

What is the CVSS score of CVE-2026-21249?

CVE-2026-21249 has a CVSS v3 base score of 3.3 (NVD).

How do I remediate CVE-2026-21249?

Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-21249, 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

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-21249

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