CVE-2018-12368

CVE-2018-12368 is a high-severity vulnerability in Mozilla Firefox with a CVSS 3.x base score of 8.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Description

Windows 10 does not warn users before opening executable files with the SettingContent-ms extension even when they have been downloaded from the internet and have the "Mark of the Web." Without the warning, unsuspecting users unfamiliar with this new file type might run an unwanted executable. This also allows a WebExtension with the limited downloads.open permission to execute arbitrary code without user interaction on Windows 10 systems. *Note: this issue only affects Windows operating systems. Other operating systems are unaffected.*. This vulnerability affects Thunderbird < 60, Thunderbird < 52.9, Firefox ESR < 60.1, Firefox ESR < 52.9, and Firefox < 61.

Frequently asked questions

What is CVE-2018-12368?
Windows 10 does not warn users before opening executable files with the SettingContent-ms extension even when they have been downloaded from the internet and have the "Mark of the Web." Without the warning, unsuspecting users unfamiliar with this new file type might run an unwanted executable. This also allows a WebExtension with the limited downloads.open permission to execute arbitrary code without user interaction on Windows 10 systems. *Note: this issue only affects Windows operating systems. Other operating systems are unaffected.*. This vulnerability affects Thunderbird < 60, Thunderbird < 52.9, Firefox ESR < 60.1, Firefox ESR < 52.9, and Firefox < 61.
How severe is CVE-2018-12368?
CVE-2018-12368 has a CVSS 3.x base score of 8.1, rated high severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2018-12368 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 5% (91st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2018-12368?
CVE-2018-12368 primarily affects Mozilla Firefox. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2018-12368?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2018-12368 published?
CVE-2018-12368 was published on 2018-10-18 and last updated on 2026-06-17.

References

Affected products (3)

More vulnerabilities in Mozilla Firefox

All CVEs affecting Mozilla Firefox →