How severe is CVE-1999-0877?

CVE-1999-0877 has a CVSS 2.0 base score of 4.3, rated medium severity.

Is CVE-1999-0877 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 18% (97th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-1999-0877?

CVE-1999-0877 primarily affects Microsoft Internet Explorer. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-1999-0877?

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

When was CVE-1999-0877 published?

CVE-1999-0877 was published on 1999-10-01 and last updated on 2026-06-16.

CVE-1999-0877

CVE-1999-0877 is a medium-severity vulnerability in Microsoft Internet Explorer with a CVSS 2.0 base score of 4.3. Its EPSS exploit-prediction score of 18% places it in the 97th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-200.

Key facts

Severity: Medium (CVSS 2.0 base score 4.3)
EPSS exploit prediction: 18% (97th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-200
Affected product: Microsoft Internet Explorer
Published: 1999-10-01
Last modified: 2026-06-16

Description

Internet Explorer 5 allows remote attackers to read files via an ExecCommand method called on an IFRAME.

Frequently asked questions

What is CVE-1999-0877?: Internet Explorer 5 allows remote attackers to read files via an ExecCommand method called on an IFRAME.
How severe is CVE-1999-0877?: CVE-1999-0877 has a CVSS 2.0 base score of 4.3, rated medium severity.
Is CVE-1999-0877 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 18% (97th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-1999-0877?: CVE-1999-0877 primarily affects Microsoft Internet Explorer. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-1999-0877?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-1999-0877 published?: CVE-1999-0877 was published on 1999-10-01 and last updated on 2026-06-16.

References

Affected products (3)

cpe:2.3:a:microsoft:internet_explorer:4.01:*:*:*:*:*:*:*
cpe:2.3:a:microsoft:internet_explorer:4.01:sp1:*:*:*:*:*:*
cpe:2.3:a:microsoft:internet_explorer:5.0:*:*:*:*:*:*:*

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