CVE-2018-20821

Name: CVE-2018-20821
Creator: NVD / NIST
Published: 2019-04-23T14:29:00.46+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.5/10EPSS 2.22%

Last modified Jun 17, 2026

CVE-2018-20821 is a medium-severity vulnerability rated 6.5/10 on the CVSS scale. The parsing component in LibSass through 3.5.5 allows attackers to cause a denial-of-service (uncontrolled recursion in Sass::Parser::parse_css_variable_value in parser.cpp).. EPSS estimates a 2.22% chance of exploitation in the next 30 days.

Description

The parsing component in LibSass through 3.5.5 allows attackers to cause a denial-of-service (uncontrolled recursion in Sass::Parser::parse_css_variable_value in parser.cpp).

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

2.22%

80.4th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-674

Affected Software

Vendor	Product	Versions
Sass-Lang	Libsass	<= 3.5.5

References

http://lists.opensuse.org/opensuse-security-announce/2019-07/msg00047.htmlBroken Link
http://lists.opensuse.org/opensuse-security-announce/2019-07/msg00051.htmlBroken Link
http://lists.opensuse.org/opensuse-security-announce/2019-08/msg00027.htmlBroken Link
https://github.com/sass/libsass/issues/2658Exploit, Patch, Third Party Advisory
http://lists.opensuse.org/opensuse-security-announce/2019-07/msg00047.htmlBroken Link
http://lists.opensuse.org/opensuse-security-announce/2019-07/msg00051.htmlBroken Link
http://lists.opensuse.org/opensuse-security-announce/2019-08/msg00027.htmlBroken Link
https://github.com/sass/libsass/issues/2658Exploit, Patch, Third Party Advisory

Timeline

Published: Apr 23, 2019
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2018-20821?

The parsing component in LibSass through 3.5.5 allows attackers to cause a denial-of-service (uncontrolled recursion in Sass::Parser::parse_css_variable_value in parser.cpp).

How severe is CVE-2018-20821?

CVE-2018-20821 has a CVSS score of 6.5/10 (MEDIUM severity). The EPSS model estimates a 2.22% probability of exploitation in the next 30 days.

How do I fix CVE-2018-20821?

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-2018-20821?

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

Scan your code now

Source: NVD / NIST