CVE-2021-30157

Name: CVE-2021-30157
Creator: NVD / NIST
Published: 2021-04-06T07:15:12.437+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.1/10EPSS 1.41%

Last modified Jun 17, 2026

CVE-2021-30157 is a medium-severity vulnerability rated 6.1/10 on the CVSS scale. An issue was discovered in MediaWiki before 1.31.12 and 1.32.x through 1.35.x before 1.35.2. On ChangesList special pages such as Special:RecentChanges and Special:Watchlist, some of the rcfilters-filter-* label messages are output in HTML unescaped, leading to XSS.. EPSS estimates a 1.41% chance of exploitation in the next 30 days.

Description

An issue was discovered in MediaWiki before 1.31.12 and 1.32.x through 1.35.x before 1.35.2. On ChangesList special pages such as Special:RecentChanges and Special:Watchlist, some of the rcfilters-filter-* label messages are output in HTML unescaped, leading to XSS.

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

1.41%

69.2th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-79

Affected Software

Vendor	Product	Versions
Mediawiki	Mediawiki	< 1.31.12
Mediawiki	Mediawiki	>= 1.32.0, < 1.35.2
Debian	Debian Linux	10.0
Fedoraproject	Fedora	33
Fedoraproject	Fedora	34

References

https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/26UJGHF7LJDOCQN6A3Z4PM7PYRKENJHE/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2OMSV7B2TCFBOCICN3B4SMQP5HVRJQIT/
https://phabricator.wikimedia.org/T278058Exploit, Issue Tracking, Patch, Vendor Advisory
https://security.gentoo.org/glsa/202107-40Third Party Advisory
https://www.debian.org/security/2021/dsa-4889Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/26UJGHF7LJDOCQN6A3Z4PM7PYRKENJHE/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2OMSV7B2TCFBOCICN3B4SMQP5HVRJQIT/
https://phabricator.wikimedia.org/T278058Exploit, Issue Tracking, Patch, Vendor Advisory
https://security.gentoo.org/glsa/202107-40Third Party Advisory
https://www.debian.org/security/2021/dsa-4889Third Party Advisory

Timeline

Published: Apr 6, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-30157?

How severe is CVE-2021-30157?

CVE-2021-30157 has a CVSS score of 6.1/10 (MEDIUM severity). The EPSS model estimates a 1.41% probability of exploitation in the next 30 days.

How do I fix CVE-2021-30157?

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-2021-30157?

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

Scan your code now

Source: NVD / NIST