How severe is CVE-1999-1189?

CVE-1999-1189 has a CVSS 2.0 base score of 7.5, rated high severity.

Is CVE-1999-1189 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (83rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-1999-1189?

CVE-1999-1189 primarily affects Netscape Communicator. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-1999-1189?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-1999-1189 published?

CVE-1999-1189 was published on 1999-11-24 and last updated on 2026-06-16.

CVE-1999-1189

CVE-1999-1189 is a high-severity vulnerability in Netscape Communicator with a CVSS 2.0 base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Severity: High (CVSS 2.0 base score 7.5)
EPSS exploit prediction: 3% (83rd percentile)
Actively exploited: Not listed in CISA KEV
Affected product: Netscape Communicator
Published: 1999-11-24
Last modified: 2026-06-16

Description

Buffer overflow in Netscape Navigator/Communicator 4.7 for Windows 95 and Windows 98 allows remote attackers to cause a denial of service, and possibly execute arbitrary commands, via a long argument after the ? character in a URL that references an .asp, .cgi, .html, or .pl file.

Frequently asked questions

What is CVE-1999-1189?: Buffer overflow in Netscape Navigator/Communicator 4.7 for Windows 95 and Windows 98 allows remote attackers to cause a denial of service, and possibly execute arbitrary commands, via a long argument after the ? character in a URL that references an .asp, .cgi, .html, or .pl file.
How severe is CVE-1999-1189?: CVE-1999-1189 has a CVSS 2.0 base score of 7.5, rated high severity.
Is CVE-1999-1189 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (83rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-1999-1189?: CVE-1999-1189 primarily affects Netscape Communicator. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-1999-1189?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-1999-1189 published?: CVE-1999-1189 was published on 1999-11-24 and last updated on 2026-06-16.

References

Affected products (2)

cpe:2.3:a:netscape:communicator:4.7:*:*:*:*:*:*:*
cpe:2.3:a:netscape:navigator:4.7:*:*:*:*:*:*:*

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