CVE-2018-20676 is a medium-severity (CVSS 6.1) Cross-site Scripting (XSS) vulnerability in org.webjars:bootstrap. A fix is available for org.webjars:bootstrap — see the affected versions and patch details below.
XSS vulnerability that affects bootstrap
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2018-20676 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 377,166 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
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.
bootstrapnpmbootstrap-sassnpmDescription
In Bootstrap before 3.4.0, XSS is possible in the tooltip data-viewport attribute.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | org.webjars:bootstrap | all versions | 3.4.0org.webjars:bootstrap:3.4.0 |
| 📦npm | bootstrap | all versions | 3.4.0npm install bootstrap@3.4.0 |
| 📦npm | bootstrap-sass | all versions | 3.4.0npm install bootstrap-sass@3.4.0 |
| .NETNuGet | bootstrap | all versions | 3.4.0dotnet add package bootstrap --version 3.4.0 |
| 🐘Packagist | twbs/bootstrap | all versions | 3.4.0composer require twbs/bootstrap:^3.4.0 |
| 💎RubyGems | bootstrap | all versions | 3.4.0bundle update bootstrap --conservative |
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, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update org.webjars:bootstrap to 3.4.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2018-20676 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 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2018-20676 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2018-20676. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
Red Hat CloudForms 4.6 and newer versions include the vulnerable component, but there is no risk of exploitation, since there is no possible vector to access the vulnerability. Older Red Hat CloudForms versions do not use the vulnerable component at all. Red Hat Virtualization 4.2 EUS contains the affected version of…
| Product | Fixed in | Advisory |
|---|---|---|
| Red Hat Decision Manager 7 | bootstrap | RHSA-2020:0133 |
| Red Hat Enterprise Linux 7 | ipa-0:4.6.8-5.el7 | RHSA-2020:3936 |
| Red Hat Enterprise Linux 8 | idm:client-8030020200923172426.05ac3f11 | RHSA-2020:4670 |
| Red Hat OpenStack Platform 13.0 (Queens) | python-XStatic-Bootstrap-SCSS-0:3.4.1.0-1.el7ost | RHSA-2020:5571 |
| Red Hat Process Automation 7 | bootstrap | RHSA-2020:0132 |
| Red Hat Single Sign-On 7.3.2 zip | bootstrap | RHSA-2019:1456 |
| Red Hat Virtualization Engine 4.3 | ovirt-engine-api-explorer-0:0.0.4-1.el7ev | RHBA-2019:1076 |
| Red Hat Virtualization Engine 4.3 | ovirt-engine-api-explorer-0:0.0.5-1.el7ev | RHBA-2019:1570 |
Frequently Asked Questions
Is CVE-2018-20676 in your dependencies?
O3 Security finds CVE-2018-20676 across Maven, npm, NuGet dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.