Is CVE-2018-12379 in the CISA KEV catalog?

No. CVE-2018-12379 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2018-12379?

CVE-2018-12379 has a CVSS v3 base score of 7.8 (HIGH).

What is the EPSS score for CVE-2018-12379?

CVE-2018-12379 has an EPSS score of 0.39% (31th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix CVE-2018-12379?

Upgrade firefox on debian unstable to 62.0-1 or later. Fixes are available for 4 affected products.

CVE & CISA-KEV Catalog

CVE-2018-12379

HIGH

7.8

CVSS v3

NVD

Description

When the Mozilla Updater opens a MAR format file which contains a very long item filename, an out-of-bounds write can be triggered, leading to a potentially exploitable crash. This requires running the Mozilla Updater manually on the local system with the malicious MAR file in order to occur. This vulnerability affects Firefox < 62, Firefox ESR < 60.2, and Thunderbird < 60.2.1.

CWE-787Out-of-bounds Write

How to fix

Remediation Available

firefoxDebian

Fixed in:62.0-1CVE-2018-12379

DeveloperEditionWindows application

Affected:62.0Fixed in:62.0Mozilla

Affected:60.2.0Fixed in:60.2.0Mozilla

Mozilla Firefox (en-US)Windows application

Affected:62.0Fixed in:62.0Mozilla

Affected:60.2.0Fixed in:60.2.0Mozilla

Mozilla Thunderbird (en-US)Windows application

Affected:60.2.1Fixed in:60.2.1Mozilla

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorLocal

Attack ComplexityLow

Privileges RequiredLow

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityHigh

IntegrityHigh

AvailabilityHigh

CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Exploit Intelligence

0.39%probability of exploitation in 30 days

31stpercentile

Low risk: more likely to be exploited than 31% of all known CVEs.

References

Vendor Advisory4

Third-Party Advisory10

Related Vulnerabilities

Other CWE-787 (Out-of-bounds Write) vulnerabilities, ordered by exploit likelihood. View all

CVE	Severity	CVSS	EPSS	Exploited	Fix
CVE-2025-22457	Critical	9.0	100%	KEV + Ransom	Fix
CVE-2025-0282	Critical	9.0	100%	KEV + Ransom	-
CVE-2015-3113	Critical	9.8	100%	KEV	Fix
CVE-2021-20038	Critical	9.8	100%	KEV + Ransom	-
CVE-2023-4863	High	8.8	100%	KEV	Fix
CVE-2020-16040	Medium	6.5	100%	-	Fix

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2025-11-25.