How severe is CVE-2020-27620?

CVE-2020-27620 has a CVSS 3.x base score of 6.1, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.

Is CVE-2020-27620 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (55th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-27620?

CVE-2020-27620 affects Mediawiki Skin. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2020-27620?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2020-27620 published?

CVE-2020-27620 was published on 2020-10-22 and last updated on 2026-06-17.

CVE-2020-27620

CVE-2020-27620 is a medium-severity vulnerability in Mediawiki Skin with a CVSS 3.x base score of 6.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-79.

Key facts

Severity: Medium (CVSS 3.x base score 6.1)
CVSS v2: 4.3
EPSS exploit prediction: 1% (55th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-79
Affected product: Mediawiki Skin
Published: 2020-10-22
Last modified: 2026-06-17

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.

Frequently asked questions

What is CVE-2020-27620?: 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.
How severe is CVE-2020-27620?: CVE-2020-27620 has a CVSS 3.x base score of 6.1, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2020-27620 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (55th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-27620?: CVE-2020-27620 affects Mediawiki Skin. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2020-27620?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2020-27620 published?: CVE-2020-27620 was published on 2020-10-22 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:mediawiki:skin\:cosmos:*:*:*:*:*:*:*:*

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