How severe is CVE-1999-0440?

CVE-1999-0440 has a CVSS 2.0 base score of 7.5, rated high severity.

Is CVE-1999-0440 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 4% (88th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-1999-0440?

CVE-1999-0440 primarily affects Netscape Communicator. In total, 13 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-1999-0440?

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-1999-0440 published?

CVE-1999-0440 was published on 1999-03-01 and last updated on 2026-06-16.

CVE-1999-0440

CVE-1999-0440 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: 4% (88th percentile)
Actively exploited: Not listed in CISA KEV
Affected product: Netscape Communicator
Published: 1999-03-01
Last modified: 2026-06-16

Description

The byte code verifier component of the Java Virtual Machine (JVM) allows remote execution through malicious web pages.

Frequently asked questions

What is CVE-1999-0440?: The byte code verifier component of the Java Virtual Machine (JVM) allows remote execution through malicious web pages.
How severe is CVE-1999-0440?: CVE-1999-0440 has a CVSS 2.0 base score of 7.5, rated high severity.
Is CVE-1999-0440 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 4% (88th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-1999-0440?: CVE-1999-0440 primarily affects Netscape Communicator. In total, 13 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-1999-0440?: 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-1999-0440 published?: CVE-1999-0440 was published on 1999-03-01 and last updated on 2026-06-16.

References

Affected products (13)

cpe:2.3:a:netscape:communicator:4.5:*:*:*:*:*:*:*
cpe:2.3:a:netscape:navigator:4.0:*:*:*:*:*:*:*
cpe:2.3:a:netscape:navigator:4.01:*:*:*:*:*:*:*
cpe:2.3:a:netscape:navigator:4.02:*:*:*:*:*:*:*
cpe:2.3:a:netscape:navigator:4.03:*:*:*:*:*:*:*
cpe:2.3:a:netscape:navigator:4.04:*:*:*:*:*:*:*
cpe:2.3:a:netscape:navigator:4.05:*:*:*:*:*:*:*
cpe:2.3:a:netscape:navigator:4.5:*:*:*:*:*:*:*
cpe:2.3:a:netscape:navigator:4.06:*:*:*:*:*:*:*
cpe:2.3:a:netscape:navigator:4.07:*:*:*:*:*:*:*
cpe:2.3:a:netscape:navigator:4.08:*:*:*:*:*:*:*
cpe:2.3:a:netscape:navigator:4.61:*:*:*:*:*:*:*
cpe:2.3:a:sun:java:*:*:*:*:*:*:*:*

More vulnerabilities in Netscape Communicator

CVE-2002-2248 — Critical (CVSS 10.0): Buffer overflow in the sun.awt.windows.WDefaultFontCharset Java class implementation in Netscape 4.0 allows remote…
CVE-2002-0593 — High (CVSS 7.5): Buffer overflow in Netscape 6 and Mozilla 1.0 RC1 and earlier allows remote attackers to cause a denial of service…
CVE-2001-0596 — High (CVSS 7.5): Netscape Communicator before 4.77 allows remote attackers to execute arbitrary Javascript via a GIF image whose comment…
CVE-2000-1187 — High (CVSS 7.5): Buffer overflow in the HTML parser for Netscape 4.75 and earlier allows remote attackers to execute arbitrary commands…
CVE-2000-0711 — High (CVSS 7.5): Netscape Communicator does not properly prevent a ServerSocket object from being created by untrusted entities, which…
CVE-1999-1189 — High (CVSS 7.5): Buffer overflow in Netscape Navigator/Communicator 4.7 for Windows 95 and Windows 98 allows remote attackers to cause a…

All CVEs affecting Netscape Communicator →