CVE-2017-5389: Mozilla Firefox

Medium severity, CVSS 6.1. EPSS: 0.9% chance of exploitation in the next 30 days.

WebExtensions could use the "mozAddonManager" API by modifying the CSP headers on sites with the appropriate permissions and then using host requests to redirect script loads to a malicious site. This allows a malicious extension to then install additional extensions without explicit user permission. This vulnerability affects Firefox < 51.

Affected products

• Mozilla Firefox: before 51.0 (fixed in 51.0)

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