CVE-2020-15669

Name: CVE-2020-15669
Creator: NVD / NIST
Published: 2020-10-01T19:15:13.407+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 8.8/10EPSS 1.11%

Last modified Jun 17, 2026

CVE-2020-15669 is a high-severity vulnerability rated 8.8/10 on the CVSS scale. When aborting an operation, such as a fetch, an abort signal may be deleted while alerting the objects to be notified. This results in a use-after-free and we presume that with enough effort it could have been exploited to run arbitrary code. EPSS estimates a 1.11% chance of exploitation in the next 30 days.

Description

When aborting an operation, such as a fetch, an abort signal may be deleted while alerting the objects to be notified. This results in a use-after-free and we presume that with enough effort it could have been exploited to run arbitrary code. This vulnerability affects Firefox ESR < 68.12 and Thunderbird < 68.12.

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

1.11%

61.6th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-416

Affected Software

Vendor	Product	Versions
Mozilla	Firefox Esr	< 68.12
Mozilla	Thunderbird	< 68.12

References

https://bugzilla.mozilla.org/show_bug.cgi?id=1656957Issue Tracking, Permissions Required, Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2020-37/Release Notes, Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2020-40/Release Notes, Vendor Advisory
https://bugzilla.mozilla.org/show_bug.cgi?id=1656957Issue Tracking, Permissions Required, Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2020-37/Release Notes, Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2020-40/Release Notes, Vendor Advisory

Timeline

Published: Oct 1, 2020
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2020-15669?

How severe is CVE-2020-15669?

CVE-2020-15669 has a CVSS score of 8.8/10 (HIGH severity). The EPSS model estimates a 1.11% probability of exploitation in the next 30 days.

How do I fix CVE-2020-15669?

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-2020-15669?

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

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Source: NVD / NIST