CVE-2021-32855 is a medium-severity (CVSS 6.1) Cross-site Scripting (XSS) vulnerability in vditor. 1 public exploit or proof-of-concept reference is indexed, so weaponization risk is real. A fix is available for vditor — see the affected versions and patch details below.
Vditor Cross-site Scripting vulnerability
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
Exploitation and automatability from CISA’s SSVC triage for CVE-2021-32855.
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.
vditornpmDescription
Vditor is a browser-side Markdown editor. Versions prior to 3.8.7 are vulnerable to copy-paste cross-site scripting (XSS). For this particular type of XSS, the victim needs to be fooled into copying a malicious payload into the text editor. Version 3.8.7 contains a patch for this issue.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | vditor | all versions | 3.8.7npm install vditor@3.8.7 |
Affected Products
vditorb3logResearch 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 vditor, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update vditor to 3.8.7 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-32855 is resolved across your whole dependency graph.
Workarounds
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-2021-32855 in your dependencies?
Find it across npm, including transitive dependencies.