What is CVE-2023-45373?

CVE-2023-45373 is a medium-severity vulnerability in MediaWiki, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2023-10-09.

How severe is CVE-2023-45373?

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

XSS in MediaWiki

CVE-2023-45373

An issue was discovered in the ProofreadPage extension for MediaWiki before 1.35.12, 1.36.x through 1.39.x before 1.39.5, and 1.40.x before 1.40.1. XSS can occur via formatNumNoSeparators.

Vulnerability class: XSS (Cross-Site Scripting)

Published 2023-10-09 · 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: 0.003 (22.7th percentile), scored 2026-10-05.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 23rd percentile — 22.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: 0.000

Affected products

MediaWiki — versions 1.40.0

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

phabricator.wikimedia.org/T345693 (Issue Tracking, Vendor Advisory)
gerrit.wikimedia.org/r/c/mediawiki/extensions/ProofreadPage/+/961262 (Issue Tracking, Vendor Advisory)

Frequently asked questions

What is CVE-2023-45373?: CVE-2023-45373 is a medium-severity vulnerability in MediaWiki, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2023-10-09.
How severe is CVE-2023-45373?: Medium severity. CVSS v3 base score is 6.1 out of 10.