What’s Vulnerable › Vulnerabilities

CVE-2018-12387

• Severity: critical (CVSS 9.1 v3.0)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 9.6% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2018-10-18 · updated 2026-06-17
• Weakness: CWE-20

Description

A vulnerability where the JavaScript JIT compiler inlines Array.prototype.push with multiple arguments that results in the stack pointer being off by 8 bytes after a bailout. This leaks a memory address to the calling function which can be used as part of an exploit inside the sandboxed content process. This vulnerability affects Firefox ESR < 60.2.2 and Firefox < 62.0.3.

Affected products

• Canonical Ubuntu Linux: 14.04, 16.04, 18.04
• Debian Linux: 9.0
• Mozilla Firefox: before 60.2.2; before 62.0.3 — fixed in 60.2.2, 62.0.3
• RedHat Enterprise Linux Desktop: 6.0, 7.0
• RedHat Enterprise Linux Server: 6.0, 7.0
• RedHat Enterprise Linux Server Aus: 7.6
• RedHat Enterprise Linux Server Eus: 7.5, 7.6
• RedHat Enterprise Linux Server Tus: 7.6
• RedHat Enterprise Linux Workstation: 6.0, 7.0

How to fix

Upgrade to a fixed version: Mozilla Firefox 60.2.2, 62.0.3. Check the vendor advisory for mitigations.

References

• http://www.securityfocus.com/bid/105460
• http://www.securitytracker.com/id/1041770
• https://access.redhat.com/errata/RHSA-2018:2881
• https://access.redhat.com/errata/RHSA-2018:2884
• https://bugzilla.mozilla.org/show_bug.cgi?id=1493903
• https://security.gentoo.org/glsa/201810-01
• https://usn.ubuntu.com/3778-1/
• https://www.debian.org/security/2018/dsa-4310
• https://www.mozilla.org/security/advisories/mfsa2018-24/
• http://www.securityfocus.com/bid/105460
• http://www.securitytracker.com/id/1041770
• https://access.redhat.com/errata/RHSA-2018:2881

Get alerted when CVE-2018-12387 or the next vulnerability affects your stack