CVE-2017-7804: Mozilla Firefox

High severity, CVSS 7.5. EPSS: 1.5% chance of exploitation in the next 30 days.

The destructor function for the "WindowsDllDetourPatcher" class can be re-purposed by malicious code in concert with another vulnerability to write arbitrary data to an attacker controlled location in memory. This can be used to bypass existing memory protections in this situation. Note: This attack only affects Windows operating systems. Other operating systems are not affected. This vulnerability affects Thunderbird < 52.3, Firefox ESR < 52.3, and Firefox < 55.

Affected products

• Mozilla Firefox: before 52.3.0 (fixed in 52.3.0); before 55.0 (fixed in 55.0)
• Mozilla Thunderbird: before 52.3.0 (fixed in 52.3.0)

Published 2018-06-11. Last modified 2026-06-17.