Answer in brief
CVE-2020-6819 records a High severity vulnerability in CVE Program Container. The current sources mark it as known exploited. The current feed maps Mozilla/Firefox (generic), Mozilla/Firefox ESR (generic), Mozilla/Thunderbird (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
A CVSS score is not reported in the current record. Known-exploitation status makes exposure review time-sensitive. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Mozilla/Firefox (generic), Mozilla/Firefox ESR (generic), Mozilla/Thunderbird (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Mozilla/Firefoxgeneric | >=unspecified <74.0.1 | 74.0.1 |
| Mozilla/Firefox ESRgeneric | >=unspecified <68.6.1 | 68.6.1 |
| Mozilla/Thunderbirdgeneric | >=unspecified <68.7.0 | 68.7.0 |
Published upstream
Apr 24, 2020
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Oct 21, 2025
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
May 24, 2026
Added to CISA KEV
Nov 3, 2021
Evidence: source:kev:kev:kev:recordUnder 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.
Quoted source text, attributed separately from HOL analysis.
Answer in brief
CVE-2020-6819 records a High severity vulnerability in CVE Program Container. The current sources mark it as known exploited. The current feed maps Mozilla/Firefox (generic), Mozilla/Firefox ESR (generic), Mozilla/Thunderbird (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
A CVSS score is not reported in the current record. Known-exploitation status makes exposure review time-sensitive. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Mozilla/Firefox (generic), Mozilla/Firefox ESR (generic), Mozilla/Thunderbird (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Mozilla/Firefoxgeneric | >=unspecified <74.0.1 | 74.0.1 |
| Mozilla/Firefox ESRgeneric | >=unspecified <68.6.1 | 68.6.1 |
| Mozilla/Thunderbirdgeneric | >=unspecified <68.7.0 | 68.7.0 |
Published upstream
Apr 24, 2020
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Oct 21, 2025
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
May 24, 2026
Added to CISA KEV
Nov 3, 2021
Evidence: source:kev:kev:kev:recordUnder 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.
Quoted source text, attributed separately from HOL analysis.