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.
CVE-2018-12376
CRITICALNVD 9.89.8—
EchelonGraph scoreMEDIUM confidence
Score 9.8 from GitHub Security Advisory (severity: CRITICAL) published 2022-05-14. NVD baseline CVSS 9.8; sources differ by 0.0.
Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
9.8
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
- High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 3%CVSS: 9.8Exploit: NoneExposed: 0
A fix is available — apply it.
- CVSS v3
- 9.8
- EG Score
- 9.8(medium)
- EPSS
- 86.4%
- KEV
- Not listed
Published
October 18, 2018
Last Modified
November 25, 2025
Advisory Details (10)
Auto-updated Jun 25, 2026Patch available. Sources: redhat.
generic
Mozilla Thunderbird: Multiple vulnerabilities (GLSA 201811-13) — Gentoo security
https://security.gentoo.org/glsa/201811-13generic
Mozilla Firefox: Multiple vulnerabilities (GLSA 201810-01) — Gentoo security
https://security.gentoo.org/glsa/201810-01generic Patch Available
[SECURITY] [DLA 1575-1] thunderbird security update
https://lists.debian.org/debian-lts-announce/2018/11/msg00011.htmlredhat Patch Available
Affected: Red Hat Enterprise Linux 7.
https://access.redhat.com/errata/RHSA-2018:3458redhat Patch Available
Affected: Red Hat Enterprise Linux 6.
https://access.redhat.com/errata/RHSA-2018:3403redhat Patch Available
Affected: Red Hat Enterprise Linux 6.
https://access.redhat.com/errata/RHSA-2018:2693redhat Patch Available
Affected: Red Hat Enterprise Linux 7.
https://access.redhat.com/errata/RHSA-2018:2692Vendor Advisories for CVE-2018-12376(2)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
Frequently asked(5)
What is CVE-2018-12376?
CVE-2018-12376 is a critical vulnerability published on October 18, 2018. 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 <…
When was CVE-2018-12376 disclosed?
CVE-2018-12376 was first published in the National Vulnerability Database on October 18, 2018, with the most recent update on November 25, 2025. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2018-12376 actively exploited?
CVE-2018-12376 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 86.4% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2018-12376?
CVE-2018-12376 has a CVSS v3 base score of 9.8 (NVD).
How do I remediate CVE-2018-12376?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2018-12376, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.
Dependency Blast Radius
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