kbrain

CVE-2014-8639

MEDIUM · CVSS 6.8EPSS 1.9%EU EUVD

Mozilla Firefox before 35.0, Firefox ESR 31.x before 31.4, Thunderbird before 31.4, and SeaMonkey before 2.32 do not properly interpret Set-Cookie headers within responses that have a 407 (aka Proxy Authentication Required) status code, which allows remote HTTP proxy servers to conduct session fixation attacks by providing a cookie name that corresponds to the session cookie of the origin server.

Key facts

CVSS score
6.8 (v2.0)
Severity
MEDIUM
CVSS vector
AV:N/AC:M/Au:N/C:P/I:P/A:P
EPSS score
1.9% (80th percentile)
In CISA KEV
No
In EU EUVD
Yes (EUVD-2014-8476)
Published
January 14, 2015
NVD last modified
June 17, 2026
Status
Modified

EU Vulnerability Database (EUVD)

This vulnerability is also tracked by ENISA as EUVD-2014-8476 in the EU Vulnerability Database. Last updated in EUVD on August 6, 2024.

View on the EU Vulnerability Database

Affected products

  • mozilla / firefox
  • mozilla / firefox
  • mozilla / firefox
  • mozilla / firefox
  • mozilla / firefox
  • mozilla / firefox esr
  • mozilla / seamonkey
  • mozilla / thunderbird

References

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

Query CVEs from your AI assistant

The CVE/NVD Explorer brain answers CVE questions directly inside Claude, ChatGPT, or any MCP assistant — always up to date, no setup. Add it once and stop pasting advisories into chat.

Add the CVE brain