No exploitation reportedFix available

CVE-2018-12376

Q: Is CVE-2018-12376 actively exploited?

Active exploitation of CVE-2018-12376 has not been confirmed. Its EPSS score was 3.1% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

Q: What is the CVSS score for CVE-2018-12376?

CVE-2018-12376 has a CVSS v3 base score of 9.8 (CRITICAL severity), with vector string CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

No exploitation reported by the sources we read.

Published2018-10-18
WeaknessCWE-119

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

Memory safety bugs present in Firefox 61 and Firefox ESR 60.1. Some of these bugs showed evidence of memory corruption and we presume that with enough effort that some of these could be exploited to run arbitrary code. This vulnerability affects Firefox < 62, Firefox ESR < 60.2, and Thunderbird < 60.2.1.

Timeline

dates in UTC

2018-10-1813:29CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-10-23 18:48 UTC

Indicators tagged with this CVE, per day0 indicators over 7 days

Block these indicators

Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2018-12376?format=txt
CSV export: https://api.ismalicious.com/edl/cve/CVE-2018-12376?format=csv
TAXII collection of exploited CVEs
The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD

Canonical ubuntu linux

Branch	Affected	Fixed in	Source
14.4	= 14.04	no fix published	NVD
16.4	= 16.04	no fix published	NVD
18.4	= 18.04	no fix published	NVD

Debian debian linux

Branch	Affected	Fixed in	Source
8.0	= 8.0	no fix published	NVD
9.0	= 9.0	no fix published	NVD

Mozilla firefox

Branch	Affected	Fixed in	Source
62.0	< 62.0	62.0	NVD
60.2	< 60.2.0	60.2.0	NVD

7 more products in the sources.

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Fix

Advisories and patches

www.mozilla.orgVendor Advisory
www.mozilla.orgVendor Advisory
www.mozilla.orgVendor Advisory

Detection

Nuclei template: none so far
Exploit-DB: no entry
Proof-of-concept repositories: none listed

Sources

NVDCVSS 3.09.8read 2026-10-23
NVDCVSS 2.07.5read 2026-10-23
NVDweakness (CWE)CWE-119read 2026-10-23
FIRST EPSSEPSS score3.1 %2026-10-22

Technical details

CVSS v3 Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Published: 2018-10-18
Last Modified: 2026-06-17
NVD status: Modified

Frequently asked questions

What is CVE-2018-12376?

Is CVE-2018-12376 actively exploited?

Active exploitation of CVE-2018-12376 has not been confirmed. Its EPSS score was 3.1% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2018-12376?

CVE-2018-12376 has a CVSS v3 base score of 9.8 (CRITICAL severity), with vector string CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

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