CVE-2020-12426
CVSS v3
8.8
HIGH
EPSS Score
1.6 %
exploit probability, as of 2026-09-25
CISA KEV
No
known exploited
Exploitation
—
SSVC status
Description
Mozilla developers and community members reported memory safety bugs present in Firefox 77. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox < 78.
Technical details
- Published
- 2020-07-09
Frequently asked questions
What is CVE-2020-12426?
Mozilla developers and community members reported memory safety bugs present in Firefox 77. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox < 78.
Is CVE-2020-12426 actively exploited?
Active exploitation of CVE-2020-12426 has not been confirmed. Its EPSS score was 1.6% on 2026-09-25, the estimated probability of exploitation in the next 30 days.
What is the CVSS score for CVE-2020-12426?
CVE-2020-12426 has a CVSS v3 base score of 8.8 (HIGH severity).
Is CVE-2020-12426 affecting your environment?
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