What is CVE-2021-36125?

CVE-2021-36125 is a high-severity vulnerability in MediaWiki, classified under Loop with Unreachable Exit Condition (Infinite Loop). CVSS score: 7.5/10. Published 2021-07-02.

How severe is CVE-2021-36125?

High severity. CVSS v3 base score is 7.5 out of 10.

Vulnerability in MediaWiki

CVE-2021-36125

An issue was discovered in the CentralAuth extension in MediaWiki through 1.36. The Special:GlobalRenameRequest page is vulnerable to infinite loops and denial of service attacks when a user's current username is beyond an arbitrary maximum configuration value (MaxNameChars).

Published 2021-07-02 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.010 (62.5th percentile), scored 2026-09-29.

Low probability of exploitation in the next 30 days, but still tracked. 63rd percentile — 62.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.010 · newest: 0.010 · change: 0.000

Affected products

MediaWiki

Weakness classification (CWE)

CWE-835 — Loop with Unreachable Exit Condition (Infinite Loop)

References

phabricator.wikimedia.org/T260865 (Exploit, Patch, Issue Tracking, Vendor Advisory)
gerrit.wikimedia.org/r/q/I97d8b3236b5abed8ba9a9c4d3ab5050c2e782c22 (Patch, Vendor Advisory)

Frequently asked questions

What is CVE-2021-36125?: CVE-2021-36125 is a high-severity vulnerability in MediaWiki, classified under Loop with Unreachable Exit Condition (Infinite Loop). CVSS score: 7.5/10. Published 2021-07-02.
How severe is CVE-2021-36125?: High severity. CVSS v3 base score is 7.5 out of 10.