CVE-2020-27620

MEDIUM 6.1CVE-2020-27620 · Published 22/10/2020 · updated 17/06/2026

In short

CVE-2020-27620 is a MEDIUM (CVSS 6.1) vulnerability affecting skin (mediawiki).
Chance of exploitation in the next 30 days (EPSS): 1.1%, higher than 66.3% of all vulnerabilities.
No patched version is listed yet: follow the vendor's advisory in References.

Package	Affected versions	Patched versions
skin mediawiki	`≤ 1.35.0`	No fix yet

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.

References

gerrit.wikimedia.org/r/c/mediawiki/skins/Cosmos/+/634749 · Vendor Advisory
gerrit.wikimedia.org/r/c/mediawiki/skins/Cosmos/+/634751 · Vendor Advisory
gerrit.wikimedia.org/r/c/mediawiki/skins/Cosmos/+/634752 · Vendor Advisory
phabricator.wikimedia.org/T265440 · Vendor Advisory

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