CVE-2006-2783

CVE-2006-2783 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

Description

Mozilla Firefox and Thunderbird before 1.5.0.4 strip the Unicode Byte-order-Mark (BOM) from a UTF-8 page before the page is passed to the parser, which allows remote attackers to conduct cross-site scripting (XSS) attacks via a BOM sequence in the middle of a dangerous tag such as SCRIPT.

Frequently asked questions

What is CVE-2006-2783?
Mozilla Firefox and Thunderbird before 1.5.0.4 strip the Unicode Byte-order-Mark (BOM) from a UTF-8 page before the page is passed to the parser, which allows remote attackers to conduct cross-site scripting (XSS) attacks via a BOM sequence in the middle of a dangerous tag such as SCRIPT.
How severe is CVE-2006-2783?
CVE-2006-2783 has a CVSS 2.0 base score of 4.3, rated medium severity.
Is CVE-2006-2783 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (74th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2006-2783?
CVE-2006-2783 primarily affects Mozilla Firefox. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2006-2783?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2006-2783 published?
CVE-2006-2783 was published on 2006-06-02 and last updated on 2026-06-16.

References

Affected products (2)

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