The Bootstrap latest version is 5.3.8, released on August 25, 2025, and running an outdated Bootstrap is a real security decision, not just a cosmetic one. Older major versions carry known cross-site scripting vulnerabilities in components like tooltips and popovers, and Bootstrap 3 and 4 depend on jQuery versions that are themselves past end of life. Knowing exactly which version you ship, and whether it is still maintained, is the first step to deciding whether your frontend framework is a liability. This guide covers the current release, the support picture, and the security reasons to move off old versions.
What the Bootstrap latest version is right now
As of this writing, 5.3.8 is the latest stable Bootstrap release. It shipped on August 25, 2025, and the maintainers have signaled it is expected to be the final patch on the 5.3 line before 5.4 arrives. Bootstrap 5 remains the actively supported major version, with 5.3.x serving as the production standard. Bootstrap 6 is in active development but is not yet the version you install by default.
You can confirm what you actually have installed rather than what you think you have:
npm ls bootstrap
# or check the pinned version directly
grep '"bootstrap"' package.json
If you load Bootstrap from a CDN instead of npm, the version is in the URL, and it is worth auditing because CDN links tend to get copied between projects and quietly go stale for years.
Why the version number is a security concern
Bootstrap is client-side code that runs in every visitor's browser, so a vulnerability in the version you ship is a vulnerability in your users' sessions. The most cited example is CVE-2019-8331, a cross-site scripting flaw in the tooltip and popover components: the data-template, data-content, and related attributes were not sufficiently sanitized, so attacker-controlled markup could execute. It was fixed in Bootstrap 3.4.1 and 4.3.1. Earlier component XSS issues (in the 3.x line's data attributes) were patched across the 3.4.x and 4.3.x releases as well.
The pattern is consistent: the security fixes landed in the latest patch of each maintained line, and projects that pinned an old minor version never received them. If you are on 4.2.x or any 3.x release, you are missing patches that have existed for years.
The jQuery problem in Bootstrap 3 and 4
There is a second, structural reason to be on Bootstrap 5. Versions 3 and 4 require jQuery, and they pull in a jQuery version that is itself well past its supported life. That means a Bootstrap 4 project is not just carrying Bootstrap's own risk — it is carrying an unmaintained jQuery dependency with its own history of prototype-pollution and XSS advisories. Bootstrap 5 dropped the jQuery dependency entirely, rewriting its JavaScript in vanilla ES modules. Upgrading to the Bootstrap latest version removes an entire transitive dependency and its accumulated risk in one move.
Which Bootstrap versions are still maintained
The support picture is straightforward:
- Bootstrap 5 — actively maintained;
5.3.8is current. This is where security patches land. - Bootstrap 4 — end of life. No further releases, no security patches.
- Bootstrap 3 — long past end of life.
- Bootstrap 2 — historical only.
"End of life" is the important phrase for security teams. Once a major version is EOL, a newly discovered vulnerability in it will never be fixed upstream. Your only options become a paid extended-support vendor or an upgrade. Staying on an EOL frontend framework is accepting unpatched risk indefinitely.
Upgrading safely to the latest version
Moving from Bootstrap 4 to 5 is a real migration because of the jQuery removal and class renames, but it is well documented. Do it incrementally:
npm install bootstrap@5.3.8
Then work through the JavaScript first, since that is where the jQuery dependency lived. Bootstrap 5 components initialize through the exported ES module API rather than jQuery plugins. After the JavaScript, sweep the markup for renamed utility classes (many ml-*/mr-* spacing classes became ms-*/me-* for logical properties, data-toggle became data-bs-toggle, and so on). A find-and-replace pass catches most of it; visual regression testing catches the rest.
If you cannot upgrade immediately, at minimum move to the latest patch of your current major line so you have every fix that exists for it, and add a policy check that fails the build on end-of-life frontend dependencies. An SCA tool such as Safeguard can flag both an outdated Bootstrap version with a known CVE and the transitive jQuery dependency it drags along, including cases where Bootstrap arrives through a theme package rather than your direct dependencies.
Keeping your version current going forward
The maintenance habit that prevents this whole problem is small: pin the exact version in package.json, watch for new releases with Dependabot or Renovate, and treat a frontend-framework major going EOL as a scheduled migration rather than a surprise. Loading Bootstrap from a CDN? Pin the full version in the URL and review it on the same cadence as your npm dependencies, because a hardcoded CDN link is exactly the kind of thing that stays on a vulnerable version for years without anyone noticing. Our 10 npm security best practices cover the version-pinning and monitoring workflow in more depth.
FAQ
What is the Bootstrap latest version?
Bootstrap 5.3.8, released August 25, 2025, is the latest stable version. Bootstrap 5 is the actively maintained major line; 5.4 is planned and Bootstrap 6 is in development.
Is it safe to use an old version of Bootstrap?
Not really. Older versions carry unpatched XSS issues such as CVE-2019-8331 in tooltips and popovers, and Bootstrap 3 and 4 are end of life, so no new security fixes will be released for them.
Do I still need jQuery with the latest Bootstrap?
No. Bootstrap 5 removed the jQuery dependency and uses vanilla ES modules. Upgrading from Bootstrap 4 to 5 eliminates an unmaintained jQuery dependency along with its own security history.
How do I upgrade to the Bootstrap latest version safely?
Install bootstrap@5.3.8, migrate the JavaScript off jQuery plugin initialization to the ES module API, sweep for renamed classes and data-bs-* attributes, and validate with visual regression tests before shipping.