Coverage › CVE-2020-6820
CVE-2020-6820 Unmapped
Mozilla Firefox And Thunderbird Use-After-Free Vulnerability
- Vendor / product
- Mozilla — Firefox and Thunderbird
- Description (CISA)
- 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.
- Added to KEV
- 2021-11-03
- Due date
- 2022-05-03
- Required action
- Apply updates per vendor instructions.
- Known ransomware use
- Unknown
- CWE
- CWE-362
- CISA notes
- https://nvd.nist.gov/vuln/detail/CVE-2020-6820
- Elsewhere
- cve.org · NVD · CISA KEV · JSON
ATT&CK techniques
No public source states how this vulnerability is exploited in ATT&CK terms.
The only authoritative CVE → ATT&CK mapping in the open — CTID's Mappings Explorer, pinned to a KEV snapshot of 2025-07-28 and ATT&CK 16.1 — does not include CVE-2020-6820. CISA's catalogue carries no technique field. kevmap does not infer techniques from the CWE (CWE-362) — here is why — and does not guess.
This page will change state automatically if a mapping is published. What is shown above is everything CISA publishes about the entry.