Bootstrap security updates, in plain English

Bootstrap

91,201 sites report using it · on drupal.org · 1 security update explained here

This theme provides the Bootstrap front end framework as a Drupal design.

Below is every security update for Bootstrap that this site has covered, newest first. Each one says who could exploit it, whether it applies to your site, how urgent it is, and what to tell your developer. If your site uses this theme and you are not sure which version, that is the first question to ask whoever looks after it.

Bootstrap

Moderately critical · Theme · 91,201 sites report using it · SA-CONTRIB-2026-236 · on drupal.org · Week of 21 October 2026

The theme did not sufficiently filter certain attributes which could lead to a vulnerability where malicious scripts are run. An ordinary account on the site could view restricted information and alter or add new data through these scripts.

Who could do thisOnly someone with a login on your site.
Does it apply to youThe optional tooltip and popover features must be enabled.
Has it been used in attacksNo sign of it.
How urgentDrupal rates this moderately critical. Include it in your next routine update, within the month.

Tell your developerUpdate Bootstrap to 8.x-3.45.

For developers: what the fix changed

The fix removes `sanitize`, `sanitizeFn`, and `whiteList` properties from the element's data attributes before passing them as options to the Bootstrap popover and tooltip plugins in `js/popover.js` and `js/tooltip.js`, preventing attackers from bypassing the sanitizer.

Also in this release The release also updates the Bootstrap library version from 3.4.9 to 3.4.10 and adds automated tests for the new sanitizer behaviour.

8.x-3.44 to 8.x-3.45 1 commit, 14 files including 2 tests.

docs/Theme-Settings.md +10 −10
js/popover.js +8 −1 fix
js/tooltip.js +8 −1 fix
src/Bootstrap.php +2 −1
src/Plugin/Provider/ApiProviderBase.php +4 −3
src/Plugin/Provider/CdnAsset.php +4 −3
src/Plugin/Provider/DrupalBootstrapStyles.php +1 −0
src/Plugin/Setting/Advanced/Cdn/CdnCustom.php +6 −6
src/Plugin/Setting/Advanced/Cdn/CdnCustomCss.php +1 −1
src/Plugin/Setting/Advanced/Cdn/CdnCustomCssMin.php +1 −1
src/Plugin/Setting/Advanced/Cdn/CdnCustomJs.php +1 −1
src/Plugin/Setting/Advanced/Cdn/CdnCustomJsMin.php +1 −1

Full diff, 8.x-3.44 to 8.x-3.45

The comparison is against the release immediately before the fix. If your site is on an older release, more will have changed.

Get in touch

Tell me who you are, what your organisation does, and what you need. That might be a Drupal site that needs looking after, an upgrade to get done before December, or an agency that needs Drupal cover.

If I can help, I'll say so and suggest a call. If I can't, I'll tell you straight away rather than waste your time.

For context: I work mainly with UK membership bodies, charities and research organisations, and with the agencies that look after their websites. Not recruiters.

Or start smaller and connect with me on LinkedIn. That's where I post what I find digging around in charity and grants data, and where the free tools turn up first.

Bootstrap

Bootstrap

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