Is CVE-2009-4630 being actively exploited?

CVE-2009-4630 is not currently listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.

What is the CVSS score for CVE-2009-4630?

CVE-2009-4630 has a CVSS 2.0 base score of 5.0 (MEDIUM).

CVE-2009-4630

MEDIUM · CVSS 5.0EPSS 1.0%EU EUVD

Mozilla Necko, as used in Firefox, SeaMonkey, and other applications, performs DNS prefetching of domain names contained in links within local HTML documents, which makes it easier for remote attackers to determine the network location of the application's user by logging DNS requests. NOTE: the vendor disputes the significance of this issue, stating "I don't think we necessarily need to worry about that case."

Key facts

CVSS score: 5.0 (v2.0)
Severity: MEDIUM
CVSS vector: AV:N/AC:L/Au:N/C:P/I:N/A:N
Weakness (CWE): CWE-200
EPSS score: 1.0% (64th percentile)
In CISA KEV: No
In EU EUVD: Yes (EUVD-2009-4595)
Published: January 29, 2010
NVD last modified: June 16, 2026
Status: Modified

EU Vulnerability Database (EUVD)

This vulnerability is also tracked by ENISA as EUVD-2009-4595 in the EU Vulnerability Database. Last updated in EUVD on September 17, 2024.

View on the EU Vulnerability Database

Affected products

mozilla / firefox
mozilla / seamonkey
mozilla / thunderbird

References

Last updated September 17, 2026 · Source: NVD, CISA KEV, FIRST.org EPSS

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