What is CVE-2020-25827?

CVE-2020-25827 is a high-severity vulnerability in MediaWiki, classified under Improper Restriction of Excessive Authentication Attempts. CVSS score: 7.5/10. Published 2020-09-27.

How severe is CVE-2020-25827?

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

Vulnerability in MediaWiki

CVE-2020-25827

An issue was discovered in the OATHAuth extension in MediaWiki before 1.31.10 and 1.32.x through 1.34.x before 1.34.4. For Wikis using OATHAuth on a farm/cluster (such as via CentralAuth), rate limiting of OATH tokens is only done on a single site level. Thus, multiple requests can be made across many wikis/sites concurrently.

Published 2020-09-27 · 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:H/A:N.

EPSS exploit prediction

EPSS: 0.017 (76.4th percentile), scored 2026-10-01.

Low probability of exploitation in the next 30 days, but still tracked. 76th percentile — 76.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.018 · newest: 0.017 · change: -0.000

Affected products

MediaWiki
Fedoraproject Fedora — versions 33

Weakness classification (CWE)

CWE-307 — Improper Restriction of Excessive Authentication Attempts

References

phabricator.wikimedia.org/T251661 (Exploit, Vendor Advisory)
lists.wikimedia.org/pipermail/mediawiki-l/2020-September/048480.html (Mailing List, Vendor Advisory)
lists.wikimedia.org/pipermail/mediawiki-l/2020-September/048488.html (Mailing List, Vendor Advisory)
lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/… (vendor-advisory)

Frequently asked questions

What is CVE-2020-25827?: CVE-2020-25827 is a high-severity vulnerability in MediaWiki, classified under Improper Restriction of Excessive Authentication Attempts. CVSS score: 7.5/10. Published 2020-09-27.
How severe is CVE-2020-25827?: High severity. CVSS v3 base score is 7.5 out of 10.