How severe is CVE-2020-27957?

CVE-2020-27957 has a CVSS 3.x base score of 5.4, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.

Is CVE-2020-27957 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (43rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-27957?

CVE-2020-27957 affects Mediawiki. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2020-27957?

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

When was CVE-2020-27957 published?

CVE-2020-27957 was published on 2020-10-28 and last updated on 2026-06-17.

CVE-2020-27957

CVE-2020-27957 is a medium-severity vulnerability in Mediawiki with a CVSS 3.x base score of 5.4. 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 5.4)
CVSS v2: 3.5
EPSS exploit prediction: 1% (43rd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-79
Affected product: Mediawiki
Published: 2020-10-28
Last modified: 2026-06-17

Description

The RandomGameUnit extension for MediaWiki through 1.35 was not properly escaping various title-related data. When certain varieties of games were created within MediaWiki, their names or titles could be manipulated to generate stored XSS within the RandomGameUnit extension.

Frequently asked questions

What is CVE-2020-27957?: The RandomGameUnit extension for MediaWiki through 1.35 was not properly escaping various title-related data. When certain varieties of games were created within MediaWiki, their names or titles could be manipulated to generate stored XSS within the RandomGameUnit extension.
How severe is CVE-2020-27957?: CVE-2020-27957 has a CVSS 3.x base score of 5.4, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2020-27957 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (43rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-27957?: CVE-2020-27957 affects Mediawiki. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2020-27957?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2020-27957 published?: CVE-2020-27957 was published on 2020-10-28 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:mediawiki:mediawiki:*:*:*:*:*:*:*:*

More vulnerabilities in Mediawiki

CVE-2025-67484 — Critical (CVSS 9.8): Vulnerability in Wikimedia Foundation MediaWiki. This vulnerability is associated with program files…
CVE-2024-34502 — Critical (CVSS 9.8): An issue was discovered in WikibaseLexeme in MediaWiki before 1.39.6, 1.40.x before 1.40.2, and 1.41.x before 1.41.1.…
CVE-2023-37303 — Critical (CVSS 9.8): An issue was discovered in the CheckUser extension for MediaWiki through 1.39.3. In certain situations, an attempt to…
CVE-2023-29141 — Critical (CVSS 9.8): An issue was discovered in MediaWiki before 1.35.10, 1.36.x through 1.38.x before 1.38.6, and 1.39.x before 1.39.3. An…
CVE-2022-29906 — Critical (CVSS 9.8): The admin API module in the QuizGame extension for MediaWiki through 1.37.2 (before…
CVE-2022-29904 — Critical (CVSS 9.8): The SemanticDrilldown extension for MediaWiki through 1.37.2 (before e688bdba6434591b5dff689a45e4d53459954773) allows…

All CVEs affecting Mediawiki →

Other CWE-79 (Cross-site Scripting (XSS)) vulnerabilities

CVE-2025-49410 — Critical (CVSS 10.0): Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in Imran Emu TC…
CVE-2024-47875 — Critical (CVSS 10.0): DOMPurify is a DOM-only, super-fast, uber-tolerant XSS sanitizer for HTML, MathML and SVG. DOMpurify was vulnerable to…
CVE-2024-6886 — Critical (CVSS 10.0): Improper Neutralization of Input During Web Page Generation (XSS or 'Cross-site Scripting') vulnerability in Gitea…
CVE-2023-45144 — Critical (CVSS 10.0): com.xwiki.identity-oauth:identity-oauth-ui is a package to aid in building identity and service providers based on…
CVE-2023-45138 — Critical (CVSS 10.0): Change Request is an pplication allowing users to request changes on a wiki without publishing the changes directly.…
CVE-2022-4361 — Critical (CVSS 10.0): Keycloak, an open-source identity and access management solution, has a cross-site scripting (XSS) vulnerability in the…

Browse all CWE-79 (Cross-site Scripting (XSS)) vulnerabilities →