CVE-2021-33295 is a medium-severity (CVSS 5.4) Cross-site Scripting (XSS) vulnerability in joplin. 1 public exploit or proof-of-concept reference is indexed, so weaponization risk is real. A fix is available for joplin — see the affected versions and patch details below.
Joplin Cross Site Scripting Vulnerability via NOSCRIPT tags
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.
joplinnpmDescription
Cross Site Scripting (XSS) vulnerability in Joplin Desktop App before 1.8.5 allows attackers to execute aribrary code due to improper sanitizing of html.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | joplin | all versions | 1.8.5npm install joplin@1.8.5 |
Affected Products
joplinjoplin_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 joplin, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update joplin to 1.8.5 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-33295 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-2021-33295 in your dependencies?
Find it across npm, including transitive dependencies.