CVE-2020-12417
CVSS v3
8.8
HIGH
EPSS Score
2.7 %
exploit probability, as of 2026-09-25
CISA KEV
No
known exploited
Exploitation
—
SSVC status
Description
Due to confusion about ValueTags on JavaScript Objects, an object may pass through the type barrier, resulting in memory corruption and a potentially exploitable crash. *Note: this issue only affects Firefox on ARM64 platforms.* This vulnerability affects Firefox ESR < 68.10, Firefox < 78, and Thunderbird < 68.10.0.
Technical details
- Published
- 2020-07-09
Frequently asked questions
What is CVE-2020-12417?
Due to confusion about ValueTags on JavaScript Objects, an object may pass through the type barrier, resulting in memory corruption and a potentially exploitable crash. *Note: this issue only affects Firefox on ARM64 platforms.* This vulnerability affects Firefox ESR < 68.10, Firefox < 78, and Thunderbird < 68.10.0.
Is CVE-2020-12417 actively exploited?
Active exploitation of CVE-2020-12417 has not been confirmed. Its EPSS score was 2.7% on 2026-09-25, the estimated probability of exploitation in the next 30 days.
What is the CVSS score for CVE-2020-12417?
CVE-2020-12417 has a CVSS v3 base score of 8.8 (HIGH severity).
Is CVE-2020-12417 affecting your environment?
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