How severe is CVE-2020-6794?

CVE-2020-6794 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2020-6794 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (58th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-6794?

CVE-2020-6794 primarily affects Mozilla Thunderbird. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2020-6794?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2020-6794 published?

CVE-2020-6794 was published on 2020-03-02 and last updated on 2026-06-17.

CVE-2020-6794

CVE-2020-6794 is a medium-severity vulnerability in Mozilla Thunderbird with a CVSS 3.x base score of 6.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-312.

Key facts

Severity: Medium (CVSS 3.x base score 6.5)
CVSS v2: 4.3
EPSS exploit prediction: 1% (58th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-312
Affected product: Mozilla Thunderbird
Published: 2020-03-02
Last modified: 2026-06-17

Description

If a user saved passwords before Thunderbird 60 and then later set a master password, an unencrypted copy of these passwords is still accessible. This is because the older stored password file was not deleted when the data was copied to a new format starting in Thunderbird 60. The new master password is added only on the new file. This could allow the exposure of stored password data outside of user expectations. This vulnerability affects Thunderbird < 68.5.

Frequently asked questions

What is CVE-2020-6794?: If a user saved passwords before Thunderbird 60 and then later set a master password, an unencrypted copy of these passwords is still accessible. This is because the older stored password file was not deleted when the data was copied to a new format starting in Thunderbird 60. The new master password is added only on the new file. This could allow the exposure of stored password data outside of user expectations. This vulnerability affects Thunderbird < 68.5.
How severe is CVE-2020-6794?: CVE-2020-6794 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2020-6794 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (58th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-6794?: CVE-2020-6794 primarily affects Mozilla Thunderbird. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2020-6794?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2020-6794 published?: CVE-2020-6794 was published on 2020-03-02 and last updated on 2026-06-17.

References

Affected products (4)

cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:*
cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:esm:*:*:*
cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:*
cpe:2.3:o:canonical:ubuntu_linux:19.10:*:*:*:*:*:*:*

More vulnerabilities in Mozilla Thunderbird

CVE-2026-4692 — Critical (CVSS 10.0): Sandbox escape in the Responsive Design Mode component. This vulnerability was fixed in Firefox 149, Firefox ESR…
CVE-2026-4689 — Critical (CVSS 10.0): Sandbox escape due to incorrect boundary conditions, integer overflow in the XPCOM component. This vulnerability was…
CVE-2026-2778 — Critical (CVSS 10.0): Sandbox escape due to incorrect boundary conditions in the DOM: Core & HTML component. This vulnerability was fixed in…
CVE-2026-2776 — Critical (CVSS 10.0): Sandbox escape due to incorrect boundary conditions in the Telemetry component in External Software. This vulnerability…
CVE-2026-2768 — Critical (CVSS 10.0): Sandbox escape in the Storage: IndexedDB component. This vulnerability was fixed in Firefox 148, Firefox ESR 140.8,…
CVE-2026-2761 — Critical (CVSS 10.0): Sandbox escape in the Graphics: WebRender component. This vulnerability was fixed in Firefox 148, Firefox ESR 115.33,…

All CVEs affecting Mozilla Thunderbird →

Other CWE-312 (Cleartext Storage of Sensitive Information) vulnerabilities

CVE-2022-43757 — Critical (CVSS 9.9): A Cleartext Storage of Sensitive Information vulnerability in SUSE Rancher allows users on managed clusters to gain…
CVE-2021-36782 — Critical (CVSS 9.9): A Cleartext Storage of Sensitive Information vulnerability in SUSE Rancher allows authenticated Cluster Owners, Cluster…
CVE-2020-9045 — Critical (CVSS 9.9): During installation or upgrade to Software House C•CURE 9000 v2.70 and American Dynamics victor Video Management…
CVE-2026-31848 — Critical (CVSS 9.8): Nexxt Solutions Nebula 300+ firmware through version 12.01.01.37 uses the ecos_pw cookie for authentication, which…
CVE-2025-65826 — Critical (CVSS 9.8): The mobile application was found to contain stored credentials for the network it was developed on. If an attacker…
CVE-2025-34206 — Critical (CVSS 9.8): Vasion Print (formerly PrinterLogic) Virtual Appliance Host and Application (VA and SaaS deployments) mount host…

Browse all CWE-312 (Cleartext Storage of Sensitive Information) vulnerabilities →