XSS in Malvineous Masseditregex

CVE-2025-53500

Improper Neutralization of Input During Web Page Generation (XSS or 'Cross-site Scripting') vulnerability in Wikimedia Foundation Mediawiki - MassEditRegex Extension allows Stored XSS.This issue affects Mediawiki - MassEditRegex Extension: from 1.39.X before 1.39.12, from 1.42.X before 1.42.7, from 1.43.X before 1.43.2.

Vulnerability class: XSS (Cross-Site Scripting)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 5.6 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L.

EPSS exploit prediction

EPSS: 0.003 (15.6th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 16th percentile — 15.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2025-53500: held from 0.002 to 0.003.

EPSS over last 30 days · oldest: 0.002 · newest: 0.003 · change: +0.000

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2025-53500?
CVE-2025-53500 is a medium-severity vulnerability in Malvineous Masseditregex, classified under Cross-site Scripting. CVSS score: 5.6/10. Published 2025-07-03.
How severe is CVE-2025-53500?
Medium severity. CVSS v3 base score is 5.6 out of 10.
Is CVE-2025-53500 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.