Vulnerability in Markup Markdown

CVE-2025-9540

The Markup Markdown WordPress plugin before 3.20.10 allows links to contain JavaScript which could allow users with the contributor role and above to perform Stored Cross-Site Scripting attacks.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 4.7 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:L.

EPSS exploit prediction

EPSS: 0.002 (12.6th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 13th percentile — 12.6% 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-2025-9540: held from 0.002 to 0.002.

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

Affected products

  • Markup Markdown — versions 0

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2025-9540?
CVE-2025-9540 is a medium-severity vulnerability in Markup Markdown, classified under CWE-79 CROSS-SITE SCRIPTING (XSS). CVSS score: 4.7/10. Published 2025-09-22.
How severe is CVE-2025-9540?
Medium severity. CVSS v3 base score is 4.7 out of 10.
Is CVE-2025-9540 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.