CVE-2006-1731

CVE-2006-1731 is a medium-severity vulnerability in Mozilla Firefox with a CVSS 2.0 base score of 4.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-79.

Key facts

• Severity: Medium (CVSS 2.0 base score 4.3)
• EPSS exploit prediction: 2% (76th percentile)
• Actively exploited: Not listed in CISA KEV
• Weakness: CWE-79
• Affected product: Mozilla Firefox
• Published: 2006-04-14
• Last modified: 2026-06-16

Description

Mozilla Firefox and Thunderbird 1.x before 1.5 and 1.0.x before 1.0.8, Mozilla Suite before 1.7.13, and SeaMonkey before 1.0 returns the Object class prototype instead of the global window object when (1) .valueOf.call or (2) .valueOf.apply are called without any arguments, which allows remote attackers to conduct cross-site scripting (XSS) attacks.

Frequently asked questions

What is CVE-2006-1731?

Mozilla Firefox and Thunderbird 1.x before 1.5 and 1.0.x before 1.0.8, Mozilla Suite before 1.7.13, and SeaMonkey before 1.0 returns the Object class prototype instead of the global window object when (1) .valueOf.call or (2) .valueOf.apply are called without any arguments, which allows remote attackers to conduct cross-site scripting (XSS) attacks.

How severe is CVE-2006-1731?

CVE-2006-1731 has a CVSS 2.0 base score of 4.3, rated medium severity.

Is CVE-2006-1731 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (76th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2006-1731?

CVE-2006-1731 primarily affects Mozilla Firefox. In total, 30 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2006-1731?

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

When was CVE-2006-1731 published?

CVE-2006-1731 was published on 2006-04-14 and last updated on 2026-06-16.

References

• ftp://ftp.sco.com/pub/updates/UnixWare/SCOSA-2006.26/SCOSA-2006.26.txt
• ftp://patches.sgi.com/support/free/security/advisories/20060404-01-U.asc
• http://lists.suse.com/archive/suse-security-announce/2006-Apr/0003.html
• http://secunia.com/advisories/19631
• http://secunia.com/advisories/19696
• http://secunia.com/advisories/19714
• http://secunia.com/advisories/19721
• http://secunia.com/advisories/19729
• http://secunia.com/advisories/19746
• http://secunia.com/advisories/19759
• http://secunia.com/advisories/19780
• http://secunia.com/advisories/19794
• http://secunia.com/advisories/19811
• http://secunia.com/advisories/19821
• http://secunia.com/advisories/19823
• http://secunia.com/advisories/19852
• http://secunia.com/advisories/19862
• http://secunia.com/advisories/19863
• http://secunia.com/advisories/19902
• http://secunia.com/advisories/19941
• http://secunia.com/advisories/19950
• http://secunia.com/advisories/20051
• http://secunia.com/advisories/21033
• http://secunia.com/advisories/21622
• http://sunsolve.sun.com/search/document.do?assetkey=1-26-102550-1
• http://sunsolve.sun.com/search/document.do?assetkey=1-26-228526-1
• http://support.avaya.com/elmodocs2/security/ASA-2006-205.htm
• http://www.debian.org/security/2006/dsa-1044
• http://www.debian.org/security/2006/dsa-1046
• http://www.debian.org/security/2006/dsa-1051

Affected products (30)

• cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:1.0:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:1.0.1:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:1.0.2:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:1.0.3:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:1.0.4:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:1.0.5:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:1.0.6:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:1.5:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:1.5:beta1:*:*:*:*:*:*
• cpe:2.3:a:mozilla:firefox:1.5:beta2:*:*:*:*:*:*
• cpe:2.3:a:mozilla:mozilla_suite:*:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:mozilla_suite:1.7.6:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:mozilla_suite:1.7.7:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:mozilla_suite:1.7.8:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:mozilla_suite:1.7.10:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:mozilla_suite:1.7.11:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:seamonkey:*:beta:*:*:*:*:*:*
• cpe:2.3:a:mozilla:seamonkey:1.0:*:alpha:*:*:*:*:*
• cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:thunderbird:1.0:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:thunderbird:1.0.1:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:thunderbird:1.0.2:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:thunderbird:1.0.3:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:thunderbird:1.0.4:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:thunderbird:1.0.5:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:thunderbird:1.0.5:beta:*:*:*:*:*:*
• cpe:2.3:a:mozilla:thunderbird:1.0.6:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:thunderbird:1.5:*:*:*:*:*:*:*
• cpe:2.3:a:mozilla:thunderbird:1.5:beta2:*:*:*:*:*:*

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