CVE-2020-28459 is a medium-severity (CVSS 6.1) Cross-site Scripting (XSS) vulnerability in markdown-it-decorate. 1 public exploit or proof-of-concept reference is indexed, so weaponization risk is real. The records list no fixed version yet; check the vendor advisory below and apply the mitigations in the meantime.
markdown-it-decorate vulnerable to cross-site scripting (XSS)
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.
markdown-it-decoratenpmDescription
markdown-it-decorate adds attributes, IDs and classes to Markdown, and the most recent version 1.2.2 was published in 2017. All versions are currently vulnerable to cross-site scripting (XSS) and there is no fixed version at this time
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | markdown-it-decorate | all versions | No fix |
Affected Products
markdown-it-decoratemarkdown-it-decorate_projectResearch use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for markdown-it-decorate, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Remediation status
The records we use list no patched version of markdown-it-decorate for CVE-2020-28459. Check the maintainer's advisory, and where your build allows, override or pin the dependency away from the vulnerable range.
Mitigate without a patch
Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.
Frequently Asked Questions
Is CVE-2020-28459 in your dependencies?
Find it across npm, including transitive dependencies.