CVE-2020-12389

Name: CVE-2020-12389
Creator: NVD / NIST
Published: 2020-05-26T18:15:11.153+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 10/10EPSS 1.73%

Last modified Jun 17, 2026

CVE-2020-12389 is a critical-severity vulnerability rated 10/10 on the CVSS scale. The Firefox content processes did not sufficiently lockdown access control which could result in a sandbox escape. *Note: this issue only affects Firefox on Windows operating systems.*. EPSS estimates a 1.73% chance of exploitation in the next 30 days.

Description

The Firefox content processes did not sufficiently lockdown access control which could result in a sandbox escape. *Note: this issue only affects Firefox on Windows operating systems.*. This vulnerability affects Firefox ESR < 68.8 and Firefox < 76.

Metrics

CVSS 3.1

10/10

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

EPSS Probability

1.73%

74.7th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-20

Affected Software

Vendor	Product	Versions
Mozilla	Firefox	< 76.0
Mozilla	Firefox Esr	< 68.8.0

References

https://bugzilla.mozilla.org/show_bug.cgi?id=1554110Permissions Required
https://www.mozilla.org/security/advisories/mfsa2020-16/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2020-17/Vendor Advisory
https://bugzilla.mozilla.org/show_bug.cgi?id=1554110Permissions Required
https://www.mozilla.org/security/advisories/mfsa2020-16/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2020-17/Vendor Advisory

Timeline

Published: May 26, 2020
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2020-12389?

How severe is CVE-2020-12389?

CVE-2020-12389 has a CVSS score of 10/10 (CRITICAL severity). The EPSS model estimates a 1.73% probability of exploitation in the next 30 days.

How do I fix CVE-2020-12389?

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-2020-12389?

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

Scan your code now

Source: NVD / NIST