CVE-2021-31547

Name: CVE-2021-31547
Creator: NVD / NIST
Published: 2021-04-22T03:15:08+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 4.3/10EPSS 0.87%

Last modified Jun 17, 2026

CVE-2021-31547 is a medium-severity vulnerability rated 4.3/10 on the CVSS scale. An issue was discovered in the AbuseFilter extension for MediaWiki through 1.35.2. Its AbuseFilterCheckMatch API reveals suppressed edits and usernames to unprivileged users through the iteration of crafted AbuseFilter rules.. EPSS estimates a 0.87% chance of exploitation in the next 30 days.

Description

An issue was discovered in the AbuseFilter extension for MediaWiki through 1.35.2. Its AbuseFilterCheckMatch API reveals suppressed edits and usernames to unprivileged users through the iteration of crafted AbuseFilter rules.

Metrics

CVSS 3.1

4.3/10

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N

EPSS Probability

0.87%

54.2th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-200

Affected Software

Vendor	Product	Versions
Mediawiki	Mediawiki	<= 1.35.2

References

https://gerrit.wikimedia.org/r/q/I3f7dbd8b873d411e37c8c3aac2339bf5ec36907dIssue Tracking, Third Party Advisory
https://gerrit.wikimedia.org/r/q/I4900b1be73323599d74e3164447f81eded094d75Issue Tracking, Third Party Advisory
https://phabricator.wikimedia.org/T223654Third Party Advisory
https://gerrit.wikimedia.org/r/q/I3f7dbd8b873d411e37c8c3aac2339bf5ec36907dIssue Tracking, Third Party Advisory
https://gerrit.wikimedia.org/r/q/I4900b1be73323599d74e3164447f81eded094d75Issue Tracking, Third Party Advisory
https://phabricator.wikimedia.org/T223654Third Party Advisory

Timeline

Published: Apr 22, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-31547?

How severe is CVE-2021-31547?

CVE-2021-31547 has a CVSS score of 4.3/10 (MEDIUM severity). The EPSS model estimates a 0.87% probability of exploitation in the next 30 days.

How do I fix CVE-2021-31547?

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-2021-31547?

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

Scan your code now

Source: NVD / NIST