CVE-2018-12387
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.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (9.59%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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.
- CVSS 3.0
- 9.1 CRITICALCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
- EPSS
- 9.59% probability · 95th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-20
- Affected
- redhat/enterprise linux desktop · redhat/enterprise linux server · redhat/enterprise linux server aus · redhat/enterprise linux server eus · redhat/enterprise linux server tus · redhat/enterprise linux workstation · debian/debian linux · canonical/ubuntu linux · mozilla/firefox
- Source
- security@mozilla.org
EPSS moved from 8.4% on 21 September 2026 to 9.6% on 27 October 2026. The dashed line is the ten per cent mark our analysts treat as “patch before the next change window”.
References
- http://www.securityfocus.com/bid/105460Third Party Advisory, VDB Entry
- http://www.securitytracker.com/id/1041770Third Party Advisory, VDB Entry
- https://access.redhat.com/errata/RHSA-2018:2881Third Party Advisory
- https://access.redhat.com/errata/RHSA-2018:2884Third Party Advisory
- https://bugzilla.mozilla.org/show_bug.cgi?id=1493903Exploit, Issue Tracking, Patch, Vendor Advisory
- https://security.gentoo.org/glsa/201810-01Third Party Advisory
- https://usn.ubuntu.com/3778-1/Third Party Advisory
- https://www.debian.org/security/2018/dsa-4310Third Party Advisory
- https://www.mozilla.org/security/advisories/mfsa2018-24/Vendor Advisory
- http://www.securityfocus.com/bid/105460Third Party Advisory, VDB Entry
- http://www.securitytracker.com/id/1041770Third Party Advisory, VDB Entry
- https://access.redhat.com/errata/RHSA-2018:2881Third Party Advisory
- https://access.redhat.com/errata/RHSA-2018:2884Third Party Advisory
- https://bugzilla.mozilla.org/show_bug.cgi?id=1493903Exploit, Issue Tracking, Patch, Vendor Advisory
- https://security.gentoo.org/glsa/201810-01Third Party Advisory
- https://usn.ubuntu.com/3778-1/Third Party Advisory
- https://www.debian.org/security/2018/dsa-4310Third Party Advisory
- https://www.mozilla.org/security/advisories/mfsa2018-24/Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.