CVE-2020-11721

Name: CVE-2020-11721
Creator: NVD / NIST
Published: 2020-04-12T19:15:10.367+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.5/10EPSS 0.94%

Last modified Jun 17, 2026

CVE-2020-11721 is a medium-severity vulnerability rated 6.5/10 on the CVSS scale. load_png in loader.c in libsixel.a in libsixel 1.8.6 has an uninitialized pointer leading to an invalid call to free, which can cause a denial of service.. EPSS estimates a 0.94% chance of exploitation in the next 30 days.

Description

load_png in loader.c in libsixel.a in libsixel 1.8.6 has an uninitialized pointer leading to an invalid call to free, which can cause a denial of service.

Metrics

CVSS 3.1

6.5/10

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

EPSS Probability

0.94%

56.5th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-824

Affected Software

Vendor	Product	Versions
Saitoha	Libsixel	1.8.6

References

https://github.com/saitoha/libsixel/issues/134Exploit, Third Party Advisory
https://github.com/saitoha/libsixel/issues/134Exploit, Third Party Advisory

Timeline

Published: Apr 12, 2020
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2020-11721?

load_png in loader.c in libsixel.a in libsixel 1.8.6 has an uninitialized pointer leading to an invalid call to free, which can cause a denial of service.

How severe is CVE-2020-11721?

CVE-2020-11721 has a CVSS score of 6.5/10 (MEDIUM severity). The EPSS model estimates a 0.94% probability of exploitation in the next 30 days.

How do I fix CVE-2020-11721?

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-2020-11721?

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

Scan your code now

Source: NVD / NIST