Overview
Mozilla Firefox and Thunderbird contain a race condition vulnerability when running the nsDocShell destructor under certain conditions. The race condition creates a use-after-free vulnerability, causing unspecified impacts.
https://nvd.nist.gov/vuln/detail/CVE-2020-6819
Key Details
| Property | Value |
|---|---|
| CVE ID | CVE-2020-6819 |
| Vendor / Product | Mozilla — Firefox and Thunderbird |
| NVD Published | 2020-04-24 |
| NVD Last Modified | 2025-11-04 |
| CVSS 3.1 Score | 8.1 |
| CVSS 3.1 Vector | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H |
| Severity | HIGH |
| CWE | CWE-362 |
| CISA KEV Added | 2021-11-03 |
| CISA KEV Deadline | 2022-05-03 |
| Known Ransomware Use | No |
CVSS 3.1 Breakdown
Attack Vector
Network
Attack Complexity
High
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High
Required Action
CISA BOD 22-01 Deadline: 2022-05-03.
Apply updates per vendor instructions.
Timeline
| Date | Event |
|---|---|
| 2021-11-03 | Added to CISA Known Exploited Vulnerabilities catalog |
| 2022-05-03 | CISA BOD 22-01 remediation deadline |
References
| Resource | Type |
|---|---|
| NVD — CVE-2020-6819 | Vulnerability Database |
| CISA KEV Catalog Entry | US Government |