# BookStack v26.03 — BookStack v26.03

- Product: BookStack (https://whatsnew.fyi/product/bookstack)
- Vendor: Dan Brown
- Date: 2026-03-15
- Version: v26.03
- Original notes: https://github.com/BookStackApp/BookStack/releases/tag/v26.03
- Permalink: https://whatsnew.fyi/product/bookstack/releases/v26.03

What's New is an index, not a publisher: every entry below links to the vendor's own release notes, which are the authoritative source. Entries are labelled where they are hand-curated sample data, pre-releases, or drawn from a secondary source such as a developer blog.

Reuse: the summaries, labels and curation here are © What's New. Quote freely with attribution and a link back; wholesale republication of the corpus is not permitted — terms: https://whatsnew.fyi/terms. The vendors' own release notes remain their publishers'.

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- **added** — Add new module system to the theme system
- **added** — Add logical theme events for page content render and pre-save
- **added** — Add logical theme event and class to allow inserting custom views before/after others
- **added** — Add logical theme event to allow customising the OIDC authentication URL
- **changed** — Update book delete to return to the parent shelf in a shelf context
- **changed** — Update book read API endpoint to provide parent shelf information
- **changed** — Update cursor to pointer for drawio diagrams
- **changed** — Update description for per-page display limits
- **changed** — Update emails to use the domain from the APP_URL in the SMTP HELO
- **changed** — Update translations with latest Crowdin changes
- **fixed** — Fix empty extra space showing for descriptions when the input is left empty

###### Links

- [Release video overview](https://foss.video/w/pb8WBgLhvoN78jVNrFR7Lk)
- [Update instructions](https://www.bookstackapp.com/docs/admin/updates)
- [Update details on blog](https://www.bookstackapp.com/blog/bookstack-release-v26-03/)

###### Upgrade Notices

- **Email/SMTP** - The way BookStack sends messages has changed slightly (Specifically, the SMTP HELO domain). This isn't expected to be a breaking change but testing of emails (Using the test send action in Settings > Maintenance) is advised after updating to be sure there's no impact.
- **Theme System** - Within a theme directory, the `modules/` folder is now dedicated to theme modules. If you happened to already have a folder of this name in your theme, it's advised to use a different folder name instead.

###### Full List of Changes

**Released in v26.03**

* Added new module system to the theme system. ([#5998](https://github.com/BookStackApp/BookStack/pull/5998))
* Added logical theme events for page content render and pre-save. ([#6049](https://github.com/BookStackApp/BookStack/issues/6049))
* Added logical theme event and class to allow inserting custom views before/after others. ([#5998](https://github.com/BookStackApp/BookStack/pull/5998))
* Added logical theme event to allow customising the OIDC authentication URL. ([#6014](https://github.com/BookStackApp/BookStack/issues/6014))
* Updated book delete to return to the parent shelf in a shelf context. ([#6029](https://github.com/BookStackApp/BookStack/issues/6029))
* Updated book read API endpoint to provide parent shelf information. ([#6006](https://github.com/BookStackApp/BookStack/issues/6006))
* Updated cursor to pointer for drawio diagrams. Thanks to [@lublak](https://github.com/BookStackApp/BookStack/pull/5864). ([#5864](https://github.com/BookStackApp/BookStack/pull/5864))
* Updated description for per-page display limits. ([#6005](https://github.com/BookStackApp/BookStack/issues/6005))
* Updated emails to use the domain from the APP_URL in the SMTP HELO. ([#5990](https://github.com/BookStackApp/BookStack/issues/5990))
* Updated translations with latest Crowdin changes. ([#6007](https://github.com/BookStackApp/BookStack/pull/6007))
* Fixed empty extra space showing for descriptions when the input is left empty. ([#5724](https://github.com/BookStackApp/BookStack/issues/5724))