CVE-2020-27620

Name: CVE-2020-27620
Creator: NVD / NIST
Published: 2020-10-22T04:15:11.907+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.1/10EPSS 0.87%

Last modified Jun 17, 2026

CVE-2020-27620 is a medium-severity vulnerability rated 6.1/10 on the CVSS scale. The Cosmos Skin for MediaWiki through 1.35.0 has stored XSS because MediaWiki messages were not being properly escaped. This is related to wfMessage and Html::rawElement, as demonstrated by CosmosSocialProfile::getUserGroups.. EPSS estimates a 0.87% chance of exploitation in the next 30 days.

Description

The Cosmos Skin for MediaWiki through 1.35.0 has stored XSS because MediaWiki messages were not being properly escaped. This is related to wfMessage and Html::rawElement, as demonstrated by CosmosSocialProfile::getUserGroups.

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

0.87%

54.3th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-79

Affected Software

Vendor	Product	Versions
Mediawiki	Skin\	<= 1.35.0

References

https://gerrit.wikimedia.org/r/c/mediawiki/skins/Cosmos/+/634749Vendor Advisory
https://gerrit.wikimedia.org/r/c/mediawiki/skins/Cosmos/+/634751Vendor Advisory
https://gerrit.wikimedia.org/r/c/mediawiki/skins/Cosmos/+/634752Vendor Advisory
https://phabricator.wikimedia.org/T265440Vendor Advisory
https://gerrit.wikimedia.org/r/c/mediawiki/skins/Cosmos/+/634749Vendor Advisory
https://gerrit.wikimedia.org/r/c/mediawiki/skins/Cosmos/+/634751Vendor Advisory
https://gerrit.wikimedia.org/r/c/mediawiki/skins/Cosmos/+/634752Vendor Advisory
https://phabricator.wikimedia.org/T265440Vendor Advisory

Timeline

Published: Oct 22, 2020
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2020-27620?

How severe is CVE-2020-27620?

CVE-2020-27620 has a CVSS score of 6.1/10 (MEDIUM severity). The EPSS model estimates a 0.87% probability of exploitation in the next 30 days.

How do I fix CVE-2020-27620?

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-2020-27620?

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

Scan your code now

Source: NVD / NIST