CVE-2020-15676

Name: CVE-2020-15676
Creator: NVD / NIST
Published: 2020-10-01T19:15:13.783+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.1/10EPSS 1.57%

Last modified Jun 17, 2026

CVE-2020-15676 is a medium-severity vulnerability rated 6.1/10 on the CVSS scale. Firefox sometimes ran the onload handler for SVG elements that the DOM sanitizer decided to remove, resulting in JavaScript being executed after pasting attacker-controlled data into a contenteditable element. This vulnerability affects Firefox < 81, Thunderbird < 78.3, and Firefox ESR < 78.3.. EPSS estimates a 1.57% chance of exploitation in the next 30 days.

Description

Firefox sometimes ran the onload handler for SVG elements that the DOM sanitizer decided to remove, resulting in JavaScript being executed after pasting attacker-controlled data into a contenteditable element. This vulnerability affects Firefox < 81, Thunderbird < 78.3, and Firefox ESR < 78.3.

Metrics

CVSS 3.1

6.1/10

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

EPSS Probability

1.57%

72.3th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-79

Affected Software

Vendor	Product	Versions
Mozilla	Firefox	< 81.0
Mozilla	Firefox Esr	< 78.3
Mozilla	Thunderbird	< 78.3
Debian	Debian Linux	9.0
Debian	Debian Linux	10.0
Opensuse	Leap	15.1
Opensuse	Leap	15.2

References

http://lists.opensuse.org/opensuse-security-announce/2020-10/msg00074.htmlBroken Link, Mailing List, Third Party Advisory
http://lists.opensuse.org/opensuse-security-announce/2020-10/msg00077.htmlBroken Link, Mailing List, Third Party Advisory
https://bugzilla.mozilla.org/show_bug.cgi?id=1646140Issue Tracking, Permissions Required, Vendor Advisory
https://lists.debian.org/debian-lts-announce/2020/10/msg00020.htmlMailing List, Third Party Advisory
https://security.gentoo.org/glsa/202010-02Third Party Advisory
https://www.debian.org/security/2020/dsa-4770Third Party Advisory
https://www.mozilla.org/security/advisories/mfsa2020-42/Release Notes, Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2020-43/Release Notes, Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2020-44/Release Notes, Vendor Advisory
http://lists.opensuse.org/opensuse-security-announce/2020-10/msg00074.htmlBroken Link, Mailing List, Third Party Advisory
http://lists.opensuse.org/opensuse-security-announce/2020-10/msg00077.htmlBroken Link, Mailing List, Third Party Advisory
https://bugzilla.mozilla.org/show_bug.cgi?id=1646140Issue Tracking, Permissions Required, Vendor Advisory
https://lists.debian.org/debian-lts-announce/2020/10/msg00020.htmlMailing List, Third Party Advisory
https://security.gentoo.org/glsa/202010-02Third Party Advisory
https://www.debian.org/security/2020/dsa-4770Third Party Advisory
https://www.mozilla.org/security/advisories/mfsa2020-42/Release Notes, Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2020-43/Release Notes, Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2020-44/Release Notes, Vendor Advisory

Timeline

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

Frequently Asked Questions

What is CVE-2020-15676?

How severe is CVE-2020-15676?

CVE-2020-15676 has a CVSS score of 6.1/10 (MEDIUM severity). The EPSS model estimates a 1.57% probability of exploitation in the next 30 days.

How do I fix CVE-2020-15676?

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-2020-15676?

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

Scan your code now

Source: NVD / NIST