Vulnerability in Mozilla Firefox

CVE-2021-23960

Performing garbage collection on re-declared JavaScript variables resulted in a user-after-poison, and a potentially exploitable crash. This vulnerability affects Firefox < 85, Thunderbird < 78.7, and Firefox ESR < 78.7.

EPSS: 0.012 (64.9th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.

Affected products

References

Frequently asked questions

What is CVE-2021-23960?
CVE-2021-23960 is a high-severity vulnerability in Mozilla Firefox. CVSS score: 8.8/10. Published 2021-02-26.
How severe is CVE-2021-23960?
High severity. CVSS v3 base score is 8.8 out of 10.