No exploitation reportedFix available

CVE-2020-6805

Q: Is CVE-2020-6805 actively exploited?

Active exploitation of CVE-2020-6805 has not been confirmed. Its EPSS score was 1.5% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

Q: What is the CVSS score for CVE-2020-6805?

CVE-2020-6805 has a CVSS v3 base score of 8.8 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.

No exploitation reported by the sources we read.

Published2020-03-25
WeaknessCWE-416

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

When removing data about an origin whose tab was recently closed, a use-after-free could occur in the Quota manager, resulting in a potentially exploitable crash. This vulnerability affects Thunderbird < 68.6, Firefox < 74, Firefox < ESR68.6, and Firefox ESR < 68.6.

Timeline

dates in UTC

2020-03-2522:15CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-10-23 18:48 UTC

Indicators tagged with this CVE, per day0 indicators over 7 days

Block these indicators

Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2020-6805?format=txt
CSV export: https://api.ismalicious.com/edl/cve/CVE-2020-6805?format=csv
TAXII collection of exploited CVEs
The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD

Canonical ubuntu linux

Branch	Affected	Fixed in	Source
16.4	= 16.04	no fix published	NVD
18.4	= 18.04	no fix published	NVD
19.10	= 19.10	no fix published	NVD

Mozilla firefox

Branch	Affected	Fixed in	Source
74.0	< 74.0	74.0	NVD

Mozilla firefox esr

Branch	Affected	Fixed in	Source
68.6	< 68.6.0	68.6.0	NVD

1 more product in the sources.

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Fix

Advisories and patches

www.mozilla.orgVendor Advisory
www.mozilla.orgVendor Advisory
www.mozilla.orgVendor Advisory

Detection

Nuclei template: none so far
Exploit-DB: no entry
Proof-of-concept repositories: none listed

Sources

NVDCVSS 3.18.8read 2026-10-23
NVDCVSS 2.06.8read 2026-10-23
NVDweakness (CWE)CWE-416read 2026-10-23
FIRST EPSSEPSS score1.5 %2026-10-22

Technical details

CVSS v3 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Published: 2020-03-25
Last Modified: 2026-06-17
NVD status: Modified

Frequently asked questions

What is CVE-2020-6805?

Is CVE-2020-6805 actively exploited?

Active exploitation of CVE-2020-6805 has not been confirmed. Its EPSS score was 1.5% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2020-6805?

CVE-2020-6805 has a CVSS v3 base score of 8.8 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.

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