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Not in CISA KEV
MEDIUM severity

GHSA-ph58-4vrj-w6hr bootstrap

MEDIUMFix: twbs/bootstrap#27047

GHSA-ph58-4vrj-w6hr is a medium-severity (CVSS 6.1) Cross-site Scripting (XSS) vulnerability in org.webjars:bootstrap. 1 public exploit reference exists, so weaponization risk is real. A fix is available for org.webjars:bootstrap — see the affected versions and patch details below.

bootstrap Cross-site Scripting vulnerability

Also known asCVE-2018-20677
Published
Jan 17, 2019
Updated
Sep 10, 2026
Affected
7 pkgs
Patched
7 / 7
Exploits
1 known
Exploitation data as of Sep 19, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗
4.0%probability of exploitation in next 30 days
Lower Risk0.00%
Lower risk than most CVEs90th percentile — riskier than 90% of all scored CVEsHighest risk

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

GHSA-ph58-4vrj-w6hr 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 376,715 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

7 pkgs affected

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.

15Kother npm packages depend on this — each one inherits the vulnerability until it's patched upstream
bootstrapnpm
4.7Mdownloads / week
bootstrap-sassnpm
257Kdownloads / week

Description

In Bootstrap before 3.4.0, XSS is possible in the affix configuration target property.

Affected Packages

7 total 7 fixed
EcosystemPackageVulnerable rangeFix
Mavenorg.webjars:bootstrapall versions3.4.0org.webjars:bootstrap:3.4.0
📦npmbootstrapall versions3.4.0npm install bootstrap@3.4.0
📦npmbootstrap-sassall versions3.4.0npm install bootstrap-sass@3.4.0
.NETNuGetbootstrapall versions3.4.0dotnet add package bootstrap --version 3.4.0
🐘Packagisttwbs/bootstrapall versions3.4.0composer require twbs/bootstrap:^3.4.0
💎RubyGemsbootstrapall versions3.4.0bundle update bootstrap --conservative
Exploits & PoCs
1

Research 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 dependency
  1. Detect

    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.

  2. 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 GHSA-ph58-4vrj-w6hr is resolved across your whole dependency graph.

  3. 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.

  4. How O3 protects you

    O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-ph58-4vrj-w6hr can be triaged on real exposure rather than presence alone.

Tailored to GHSA-ph58-4vrj-w6hr. 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 HatModerate

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…

ProductFixed inAdvisory
Red Hat Decision Manager 7see advisoryRHSA-2020:0133
Red Hat Enterprise Linux 7ipa-0:4.6.8-5.el7RHSA-2020:3936
Red Hat Enterprise Linux 8idm:client-8030020200923172426.05ac3f11RHSA-2020:4670
Red Hat OpenStack Platform 13.0 (Queens)python-XStatic-Bootstrap-SCSS-0:3.4.1.0-1.el7ostRHSA-2020:5571
Red Hat Process Automation 7see advisoryRHSA-2020:0132
Red Hat Single Sign-On 7.3.2 zipbootstrapRHSA-2019:1456
Red Hat Virtualization Engine 4.3ovirt-engine-api-explorer-0:0.0.4-1.el7evRHBA-2019:1076
Red Hat Virtualization Engine 4.3ovirt-engine-api-explorer-0:0.0.5-1.el7evRHBA-2019:1570

Frequently Asked Questions

In Bootstrap before 3.4.0, XSS is possible in the affix configuration target property.
O3 Security · Impact-Aware SCA

Is GHSA-ph58-4vrj-w6hr in your dependencies?

O3 Security finds GHSA-ph58-4vrj-w6hr across Maven, npm, NuGet dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.

GHSA-ph58-4vrj-w6hr: bootstrap (Medium 6.1) | O3 Security