CVE-2018-12364: Canonical Ubuntu Linux

High severity, CVSS 8.8. EPSS: 1.8% chance of exploitation in the next 30 days.

NPAPI plugins, such as Adobe Flash, can send non-simple cross-origin requests, bypassing CORS by making a same-origin POST that does a 307 redirect to the target site. This allows for a malicious site to engage in cross-site request forgery (CSRF) attacks. This vulnerability affects Thunderbird < 60, Thunderbird < 52.9, Firefox ESR < 60.1, Firefox ESR < 52.9, and Firefox < 61.

Affected products

• Canonical Ubuntu Linux: version 14.04 only; version 16.04 only; version 17.10 only; version 18.04 only
• Debian Debian Linux: version 8.0 only; version 9.0 only
• Mozilla Firefox: before 61.0 (fixed in 61.0); from 53.0, before 60.1.0 (fixed in 60.1.0)
• Mozilla Firefox ESR: before 52.9 (fixed in 52.9)
• Mozilla Thunderbird: before 52.9 (fixed in 52.9); from 52.9.1, before 60.0 (fixed in 60.0)
• Red Hat Enterprise Linux Desktop: version 6.0 only; version 7.0 only
• Red Hat Enterprise Linux Server: version 6.0 only; version 7.0 only
• Red Hat Enterprise Linux Server Aus: version 7.6 only
• Red Hat Enterprise Linux Server Eus: version 7.5 only; version 7.6 only
• Red Hat Enterprise Linux Server Tus: version 7.6 only
• Red Hat Enterprise Linux Workstation: version 6.0 only; version 7.0 only

Published 2018-10-18. Last modified 2026-06-17.