CVE-2020-6820

Under certain conditions, when handling a ReadableStream, a race condition can cause a use-after-free. We are aware of targeted attacks in the wild abusing this flaw. This vulnerability affects Thunderbird < 68.7.0, Firefox < 74.0.1, and Firefox ESR < 68.6.1.

  • Published Apr 24, 2020
  • CVSS 8.1 high
  • 7.1% chance of exploitation in the next 30 days (EPSS)
  • In CISA's Known Exploited Vulnerabilities catalog

Affected software

CVE-2020-6820 at the National Vulnerability Database