What is CVE-2021-41798?

CVE-2021-41798 is a medium-severity vulnerability in MediaWiki, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2021-10-11.

How severe is CVE-2021-41798?

Medium severity. CVSS v3 base score is 6.1 out of 10.

XSS in MediaWiki

CVE-2021-41798

MediaWiki before 1.36.2 allows XSS. Month related MediaWiki messages are not escaped before being used on the Special:Search results page.

Vulnerability class: XSS (Cross-Site Scripting)

Published 2021-10-11 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.014 (72.3th percentile), scored 2026-10-02.

Low probability of exploitation in the next 30 days, but still tracked. 72nd percentile — 72.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.013 · newest: 0.014 · change: +0.001

Affected products

MediaWiki
Fedoraproject Fedora — versions 33, 34, 35

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

phabricator.wikimedia.org/T285515 (Exploit, Patch, Third Party Advisory)
lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/… (vendor-advisory)
lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/… (vendor-advisory)
lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/… (vendor-advisory)
security.gentoo.org/glsa/202305-24 (vendor-advisory)

Frequently asked questions

What is CVE-2021-41798?: CVE-2021-41798 is a medium-severity vulnerability in MediaWiki, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2021-10-11.
How severe is CVE-2021-41798?: Medium severity. CVSS v3 base score is 6.1 out of 10.