# Mastodon v4.5.17

- Product: Mastodon (https://whatsnew.fyi/product/mastodon)
- Vendor: Mastodon gGmbH
- Date: 2026-09-01
- Version: v4.5.17
- Original notes: https://github.com/mastodon/mastodon/releases/tag/v4.5.17
- Permalink: https://whatsnew.fyi/product/mastodon/releases/v4.5.17

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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- **security** — Fix password authentication bypass in 2FA auth for LDAP/PAM/SSO accounts
- **security** — Fix Denial of Service when processing pathological JSON-LD activities
- **security** — Fix disabled staff accounts still having access to admin API
- **security** — Update dependencies
- **fixed** — Fix config/ directory missing from Bootsnap precompilation options in Dockerfile
- **fixed** — Fix various off-by-one errors in statistics time ranges

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  <img alt="Mastodon" src="./lib/assets/wordmark.light.png?raw=true" height="34">
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##### Changelog

##### Security

- Update dependencies
- Fix password authentication bypass in 2FA auth for LDAP/PAM/SSO accounts ([GHSA-vx32-x96w-qq65](https://github.com/mastodon/mastodon/security/advisories/GHSA-vx32-x96w-qq65))
- Fix Denial of Service when processing pathological JSON-LD activities ([GHSA-vgm8-frgh-rh2v](https://github.com/mastodon/mastodon/security/advisories/GHSA-vgm8-frgh-rh2v))
- Fix disabled staff accounts still having access to admin API ([GHSA-62j4-hvj7-px3f](https://github.com/mastodon/mastodon/security/advisories/GHSA-62j4-hvj7-px3f))

###### Fixes

- Fix `config/` directory missing from Bootsnap precompilation options in Dockerfile (#40255 by @ClearlyClaire)
- Fix various off-by-one errors in statistics time ranges (#40193 by @ClearlyClaire)

##### Upgrade notes

To get the code for v4.5.17, use `git fetch && git checkout v4.5.17`.

> [!NOTE]
> As always, make sure you have backups of the database before performing any upgrades. If you are using docker-compose, this is how a backup command might look: `docker exec mastodon_db_1 pg_dump -Fc -U postgres postgres > name_of_the_backup.dump`

###### Dependencies

External dependencies have not changed since v4.5.0.

- Ruby: 3.2 or newer
- PostgreSQL: 14 or newer
- Elasticsearch (recommended, for full-text search): 7.x (OpenSearch should also work)
- LibreTranslate (optional, for translations): 1.3.3 or newer
- Redis: 7.0 or newer
- Node: 20.19 or newer
- libvips (optional, instead of ImageMagick): 8.13 or newer
- ImageMagick (optional if using libvips): 6.9.7-7 or newer

###### Update steps

The following instructions are for updating from 4.5.16.

If you are upgrading directly from an earlier release, please carefully read the upgrade notes for the skipped releases as well, as they often require extra steps such as database migrations. In particular, it is very important to read the [4.5.0 release notes](https://github.com/mastodon/mastodon/releases/tag/v4.5.0).

###### Non-Docker

> [!TIP]
> The `charlock_holmes` gem may fail to build on some systems with recent versions of gcc.
If you run into this issue, try `BUNDLE_BUILD__CHARLOCK_HOLMES="--with-cxxflags=-std=c++17" bundle install`.

1. Install dependencies with `bundle install`
2. Restart all Mastodon processes.

###### When using Docker

1. Restart all Mastodon processes.