CVE-2019-8331
MEDIUMCVE-2019-8331 is a medium-severity (CVSS 6.1) Cross-site Scripting (XSS) vulnerability in org.webjars:bootstrap. 4 public exploit references exist, so weaponization risk is real. O3 Security confirms whether CVE-2019-8331 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Bootstrap Vulnerable to Cross-Site Scripting
Blast Radius
Weekly download volume for affected packages — a proxy for how broadly this vulnerability is deployed.
bootstrapnpmDescription
In Bootstrap before 3.4.1 and 4.3.x before 4.3.1, XSS is possible in the tooltip or popover data-template attribute.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | org.webjars:bootstrap | ≥ 3.0.0&&< 3.4.1 | 3.4.1 |
| ☕Maven | org.webjars:bootstrap | ≥ 4.0.0&&< 4.3.1 | 4.3.1 |
| 📦npm | bootstrap | ≥ 4.0.0&&< 4.3.1 | 4.3.1 |
| 📦npm | bootstrap | ≥ 3.0.0&&< 3.4.1 | 3.4.1 |
| 📦npm | bootstrap-sass | ≥ 3.0.0&&< 3.4.1 | 3.4.1 |
| .NETNuGet | Bootstrap.Less | ≥ 3.0.0&&< 3.4.1 | 3.4.1 |
Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
In Bootstrap before 3.4.1 and 4.3.x before 4.3.1, XSS is possible in the…
In Bootstrap before 3.4.1 and 4.3.x before 4.3.1, XSS is possible in the…
In Bootstrap before 3.4.1 and 4.3.x before 4.3.1, XSS is possible in the…
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.webjars:bootstrap. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update org.webjars:bootstrap to 3.4.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2019-8331 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2019-8331 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2019-8331. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2019-8331 in your dependencies?
O3 detects CVE-2019-8331 across Maven, npm, NuGet dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.