How severe is CVE-1999-1447?

CVE-1999-1447 has a CVSS 2.0 base score of 5.0, rated medium severity.

Is CVE-1999-1447 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 13% (96th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-1999-1447?

CVE-1999-1447 affects Microsoft Internet Explorer. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-1999-1447?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-1999-1447 published?

CVE-1999-1447 was published on 1998-07-28 and last updated on 2026-06-16.

CVE-1999-1447

CVE-1999-1447 is a medium-severity vulnerability in Microsoft Internet Explorer with a CVSS 2.0 base score of 5.0. Its EPSS exploit-prediction score of 13% places it in the 96th percentile, indicating an elevated likelihood of exploitation.

Key facts

Severity: Medium (CVSS 2.0 base score 5.0)
EPSS exploit prediction: 13% (96th percentile)
Actively exploited: Not listed in CISA KEV
Affected product: Microsoft Internet Explorer
Published: 1998-07-28
Last modified: 2026-06-16

Description

Internet Explorer 4.0 allows remote attackers to cause a denial of service (crash) via HTML code that contains a long CLASSID parameter in an OBJECT tag.

Frequently asked questions

What is CVE-1999-1447?: Internet Explorer 4.0 allows remote attackers to cause a denial of service (crash) via HTML code that contains a long CLASSID parameter in an OBJECT tag.
How severe is CVE-1999-1447?: CVE-1999-1447 has a CVSS 2.0 base score of 5.0, rated medium severity.
Is CVE-1999-1447 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 13% (96th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-1999-1447?: CVE-1999-1447 affects Microsoft Internet Explorer. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-1999-1447?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-1999-1447 published?: CVE-1999-1447 was published on 1998-07-28 and last updated on 2026-06-16.

References

Affected products (1)

cpe:2.3:a:microsoft:internet_explorer:4.0:*:*:*:*:*:*:*

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