CVE-2006-2786

CVE-2006-2786 is a low-severity vulnerability in Mozilla Firefox with a CVSS 2.0 base score of 2.6. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Description

HTTP response smuggling vulnerability in Mozilla Firefox and Thunderbird before 1.5.0.4, when used with certain proxy servers, allows remote attackers to cause Firefox to interpret certain responses as if they were responses from two different sites via (1) invalid HTTP response headers with spaces between the header name and the colon, which might not be ignored in some cases, or (2) HTTP 1.1 headers through an HTTP 1.0 proxy, which are ignored by the proxy but processed by the client.

Frequently asked questions

What is CVE-2006-2786?
HTTP response smuggling vulnerability in Mozilla Firefox and Thunderbird before 1.5.0.4, when used with certain proxy servers, allows remote attackers to cause Firefox to interpret certain responses as if they were responses from two different sites via (1) invalid HTTP response headers with spaces between the header name and the colon, which might not be ignored in some cases, or (2) HTTP 1.1 headers through an HTTP 1.0 proxy, which are ignored by the proxy but processed by the client.
How severe is CVE-2006-2786?
CVE-2006-2786 has a CVSS 2.0 base score of 2.6, rated low severity.
Is CVE-2006-2786 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (75th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2006-2786?
CVE-2006-2786 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-2006-2786?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2006-2786 published?
CVE-2006-2786 was published on 2006-06-02 and last updated on 2026-06-16.

References

Affected products (2)

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