CVE-2020-6822

Name: CVE-2020-6822
Creator: NVD / NIST
Published: 2020-04-24T16:15:13.573+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 8.8/10EPSS 1.29%

Last modified Jun 17, 2026

CVE-2020-6822 is a high-severity vulnerability rated 8.8/10 on the CVSS scale. On 32-bit builds, an out of bounds write could have occurred when processing an image larger than 4 GB in <code>GMPDecodeData</code>. It is possible that with enough effort this could have been exploited to run arbitrary code. EPSS estimates a 1.29% chance of exploitation in the next 30 days.

Description

On 32-bit builds, an out of bounds write could have occurred when processing an image larger than 4 GB in <code>GMPDecodeData</code>. It is possible that with enough effort this could have been exploited to run arbitrary code. This vulnerability affects Thunderbird < 68.7.0, Firefox ESR < 68.7, and Firefox < 75.

Metrics

CVSS 3.1

8.8/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

EPSS Probability

1.29%

66.6th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-787

Affected Software

Vendor	Product	Versions
Mozilla	Firefox	< 75.0
Mozilla	Firefox Esr	< 68.7.0
Mozilla	Thunderbird	< 68.7.0

References

https://bugzilla.mozilla.org/show_bug.cgi?id=1544181Issue Tracking, Permissions Required
https://usn.ubuntu.com/4335-1/Third Party Advisory
https://www.mozilla.org/security/advisories/mfsa2020-12/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2020-13/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2020-14/Vendor Advisory
https://bugzilla.mozilla.org/show_bug.cgi?id=1544181Issue Tracking, Permissions Required
https://usn.ubuntu.com/4335-1/Third Party Advisory
https://www.mozilla.org/security/advisories/mfsa2020-12/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2020-13/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2020-14/Vendor Advisory

Timeline

Published: Apr 24, 2020
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2020-6822?

How severe is CVE-2020-6822?

CVE-2020-6822 has a CVSS score of 8.8/10 (HIGH severity). The EPSS model estimates a 1.29% probability of exploitation in the next 30 days.

How do I fix CVE-2020-6822?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2020-6822?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST