CVE-2020-6820CISA KEVEPSS p94.0%

CVE-2020-6820Mozilla Firefox And Thunderbird Use-After-Free Vulnerability

Mozilla / Firefox and Thunderbird

Description

Mozilla Firefox and Thunderbird contain a race condition vulnerability when handling a ReadableStream under certain conditions. The race condition creates a use-after-free vulnerability, causing unspecified impacts.

Scoring

EPSS7.06% probability of exploitation · percentile 94.0% · 2026-10-05T12:00:23Z

CISA KEV entry

Added to KEV: 2021-11-03

(incoming)1

TypeTargetConfidenceTier
KEVEntryMozilla Firefox And Thunderbird Use-After-Free Vulnerabilitykev-cve-2020-68200%live

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Sourced from NVD + CISA KEV + FIRST.org EPSS. Curated for EU compliance use cases by Adam Lundqvist, Founder at SQUR.