CVE-2020-14363

Name: CVE-2020-14363
Creator: NVD / NIST
Published: 2020-09-11T18:15:13.38+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.8/10EPSS 0.57%

Last modified Jun 17, 2026

CVE-2020-14363 is a high-severity vulnerability rated 7.8/10 on the CVSS scale. An integer overflow vulnerability leading to a double-free was found in libX11. This flaw allows a local privileged attacker to cause an application compiled with libX11 to crash, or in some cases, result in arbitrary code execution. EPSS estimates a 0.57% chance of exploitation in the next 30 days.

Description

An integer overflow vulnerability leading to a double-free was found in libX11. This flaw allows a local privileged attacker to cause an application compiled with libX11 to crash, or in some cases, result in arbitrary code execution. The highest threat from this flaw is to confidentiality, integrity as well as system availability.

Metrics

CVSS 3.1

7.8/10

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

EPSS Probability

0.57%

43.0th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
X.Org	Libx11	< 1.6.12
Fedoraproject	Fedora	33

References

https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2020-14363Issue Tracking, Third Party Advisory
https://github.com/Ruia-ruia/Exploits/blob/master/DFX11details.txtThird Party Advisory
https://github.com/Ruia-ruia/Exploits/blob/master/x11doublefree.shExploit, Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/7AVXCQOSCAPKYYHFIJAZ6E2C7LJBTLXF/
https://lists.x.org/archives/xorg-announce/2020-August/003056.htmlVendor Advisory
https://usn.ubuntu.com/4487-2/Third Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2020-14363Issue Tracking, Third Party Advisory
https://github.com/Ruia-ruia/Exploits/blob/master/DFX11details.txtThird Party Advisory
https://github.com/Ruia-ruia/Exploits/blob/master/x11doublefree.shExploit, Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/7AVXCQOSCAPKYYHFIJAZ6E2C7LJBTLXF/
https://lists.x.org/archives/xorg-announce/2020-August/003056.htmlVendor Advisory
https://usn.ubuntu.com/4487-2/Third Party Advisory

Timeline

Published: Sep 11, 2020
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2020-14363?

How severe is CVE-2020-14363?

CVE-2020-14363 has a CVSS score of 7.8/10 (HIGH severity). The EPSS model estimates a 0.57% probability of exploitation in the next 30 days.

How do I fix CVE-2020-14363?

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-2020-14363?

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

Scan your code now

Source: NVD / NIST