HIGHCVSS v3.1 8.1Actively exploited · CISA KEV since 2021-11-03Vulnerability
CVE-2020-6820
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.
Properties
- Euvd product
- Firefox ESR, Thunderbird, Firefox
- Vulnerability name
- Mozilla Firefox And Thunderbird Use-After-Free Vulnerability
- First seen
- 2025-10-21T23:35:45+00:00
- Cvss score
- 8.1
- Epss score
- 0.07063
- Last seen
- 2026-10-19T12:00:27+00:00
- Due date
- 2022-05-03
- Euvd assigner
- mozilla
- Retrieved at
- 2026-10-21T01:24:47+00:00
- Exploited euvd since
- 2021-11-03T00:00:00+00:00
- Src batch id
- epss_history-20261020T103617Z-728ddd
- Source url
- https://epss.empiricalsecurity.com/epss_scores-2026-10-19.csv.gz
- Date added
- 2021-11-03
- Score
- 8.1
- Euvd base score version
- 3.1
- Fetched at
- 2026-10-20T10:36:20+00:00
- Euvd vendor
- Mozilla
- Cvss vector
- CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
- In Signal since
- initial import (Sep 2026)
- Euvd base score
- 8.1
Related Entities (6)
AFFECTS_PRODUCT (3)
DESCRIBES (1)
HAS_WEAKNESS (1)
INVOLVES (1)
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