Is CVE-2020-6819 actively exploited?

CVE-2020-6819 has no public evidence of in-the-wild exploitation as of 2025-11-04.

What is the CVSS score for CVE-2020-6819?

CVE-2020-6819 has a CVSS score of 8.1 (HIGH severity). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H.

How do I patch CVE-2020-6819?

Patch guidance is available from mozilla security advisories. CVEDatabase generates AI-assisted remediation guidance on demand for CVE-2020-6819.

Fix CVE-2020-6819 - HIGH mozilla firefox

Q: Which products are affected by CVE-2020-6819?

3 products: mozilla firefox, mozilla firefox, mozilla thunderbird.

Description

Under certain conditions, when running the nsDocShell destructor, 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.

CVSS Metrics

Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack Vector: network
Complexity: high
Privileges: none
User Action: none
Scope: unchanged
Confidentiality: high
Integrity: high
Availability: high
Weaknesses: CWE-362 · Race Condition CWE-416 · Use After Free CWE-416 · Use After Free

Metadata

Primary Vendor: MOZILLA
Published: 4/24/2020
Last Modified: 11/4/2025
Source: NIST NVD
Note: Verify all details with official vendor sources before applying patches.

CVE-2020-6819

Description

CVSS Metrics

Metadata

Affected Products

Remediation Guidance

Executive Summary