CVE-2018-5178
A buffer overflow was found during UTF8 to Unicode string conversion within JavaScript with extremely large amounts of data.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (4.89%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
A buffer overflow was found during UTF8 to Unicode string conversion within JavaScript with extremely large amounts of data. This vulnerability requires the use of a malicious or vulnerable legacy extension in order to occur. This vulnerability affects Thunderbird ESR < 52.8, Thunderbird < 52.8, and Firefox ESR < 52.8.
- CVSS 3.0
- 8.1 HIGHCVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 4.89% probability · 92th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-119
- Affected
- debian/debian linux · mozilla/firefox · mozilla/thunderbird · mozilla/thunderbird esr · canonical/ubuntu linux · 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
- Source
- security@mozilla.org
EPSS moved from 3.6% on 21 September 2026 to 4.9% on 27 October 2026, peaking at 5.0% on 22 September 2026.
References
- http://www.securityfocus.com/bid/104138Third Party Advisory, VDB Entry
- http://www.securitytracker.com/id/1040898Third Party Advisory, VDB Entry
- https://access.redhat.com/errata/RHSA-2018:1414Third Party Advisory
- https://access.redhat.com/errata/RHSA-2018:1415Third Party Advisory
- https://access.redhat.com/errata/RHSA-2018:1725Third Party Advisory
- https://access.redhat.com/errata/RHSA-2018:1726Third Party Advisory
- https://bugzilla.mozilla.org/show_bug.cgi?id=1443891Issue Tracking, Permissions Required, Vendor Advisory
- https://lists.debian.org/debian-lts-announce/2018/05/msg00007.htmlMailing List, Third Party Advisory
- https://lists.debian.org/debian-lts-announce/2018/05/msg00013.htmlMailing List, Third Party Advisory
- https://security.gentoo.org/glsa/201810-01Third Party Advisory
- https://security.gentoo.org/glsa/201811-13Third Party Advisory
- https://usn.ubuntu.com/3660-1/Third Party Advisory
- https://www.debian.org/security/2018/dsa-4199Third Party Advisory
- https://www.debian.org/security/2018/dsa-4209Third Party Advisory
- https://www.mozilla.org/security/advisories/mfsa2018-12/Vendor Advisory
- https://www.mozilla.org/security/advisories/mfsa2018-13/Vendor Advisory
- http://www.securityfocus.com/bid/104138Third Party Advisory, VDB Entry
- http://www.securitytracker.com/id/1040898Third Party Advisory, VDB Entry
- https://access.redhat.com/errata/RHSA-2018:1414Third Party Advisory
- https://access.redhat.com/errata/RHSA-2018:1415Third Party Advisory
- https://access.redhat.com/errata/RHSA-2018:1725Third Party Advisory
- https://access.redhat.com/errata/RHSA-2018:1726Third Party Advisory
- https://bugzilla.mozilla.org/show_bug.cgi?id=1443891Issue Tracking, Permissions Required, Vendor Advisory
- https://lists.debian.org/debian-lts-announce/2018/05/msg00007.htmlMailing List, Third Party Advisory
- https://lists.debian.org/debian-lts-announce/2018/05/msg00013.htmlMailing List, Third Party Advisory
- https://security.gentoo.org/glsa/201810-01Third Party Advisory
- https://security.gentoo.org/glsa/201811-13Third Party Advisory
- https://usn.ubuntu.com/3660-1/Third Party Advisory
- https://www.debian.org/security/2018/dsa-4199Third Party Advisory
- https://www.debian.org/security/2018/dsa-4209Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.