CVE-2020-26950
CVSS v3
8.8
HIGH
EPSS Score
42.3 %
exploit probability, as of 2026-10-05
CISA KEV
No
known exploited
Exploitation
—
SSVC status
Description
In certain circumstances, the MCallGetProperty opcode can be emitted with unmet assumptions resulting in an exploitable use-after-free condition. This vulnerability affects Firefox < 82.0.3, Firefox ESR < 78.4.1, and Thunderbird < 78.4.2.
Technical details
- Published
- 2020-12-09
Frequently asked questions
What is CVE-2020-26950?
In certain circumstances, the MCallGetProperty opcode can be emitted with unmet assumptions resulting in an exploitable use-after-free condition. This vulnerability affects Firefox < 82.0.3, Firefox ESR < 78.4.1, and Thunderbird < 78.4.2.
Is CVE-2020-26950 actively exploited?
Active exploitation of CVE-2020-26950 has not been confirmed. Its EPSS score was 42.3% on 2026-10-05, the estimated probability of exploitation in the next 30 days.
What is the CVSS score for CVE-2020-26950?
CVE-2020-26950 has a CVSS v3 base score of 8.8 (HIGH severity).
Is CVE-2020-26950 affecting your environment?
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