Project Zomboid Patch Notes: Latest Update (Sep 28, 2026)
Nick Guli|The latest Project Zomboid update is “Build 42.21 Stable Released”, which was posted on Steam on Sep 28, 2026. After a week in the Unstable beta, the update made its way to Stable. During that time, the community reported no major issues. This update fixes the most problematic zombie duplication and disappearing bugs. It also alters how XXL trees are cut down. Additionally, the loadstring and loadstream Lua methods are back in action.
What changed in 42.21
Bug fixes
- The worst zombie duplication issues in multiplayer are fixed.
- Zombies no longer disappear after a player leaves and re-enters a chunk, in both single player and multiplayer.
- Some instances of these issues remain and are planned for the next update.
Quality of life
- XXL trees now cut away better for players in vehicles.
- XXL trees no longer hide the houses and furniture they overhang.
- The overall transparency of XXL trees is adjusted for better visibility.
- XXL tree changes are a work in progress and will get more work in future.
Modding and server
- The loadstring and loadstream Lua methods, disabled in 42.20.4 over security vulnerabilities, are re-enabled.
- The developers apologize to modders and server admins for the disruption.
Release process
- Future releases go to Unstable first, then are tested, possibly changed, and finally released to Stable.
- The full changelist is available on the Indie Stone forums.
Read the full official patch notes on Steam.
Recent Project Zomboid updates
| Date | Update | What it does | Source |
|---|---|---|---|
| Sep 28, 2026 | Build 42.21 Stable Released | Build 42.21 moves from Unstable to Stable, fixing zombie duplication and disappearance bugs, improving XXL tree cutaway, and re-enabling two Lua methods. | Official notes |
| Sep 23, 2026 | Re-population of the Dead: Build 42.21 Unstable Released | Build 42.21 is now on the Unstable branch with fixes for vanishing and duplicated zombies, XXL tree cutaway changes, balance tweaks and multiplayer fixes. | Official notes |
| Aug 26, 2026 | 42.20.4 STABLE & 42.19.2 UNSTABLE & 41.78.21 LEGACY Hotfixes Released | Hotfixes for Stable, Unstable and Legacy branches fix security vulnerabilities and remove the loadstring and loadstream methods, which affects some mods. | Official notes |
| Aug 17, 2026 | 42.20.3 STABLE Hotfix Released | This stable hotfix improves multiplayer server player limits, fixes a Loading Map hang, and addresses memory leaks, black and gray boxes, and lighting errors. | Official notes |
| Aug 5, 2026 | 42.20.2 STABLE Hotfix Released | This stable hotfix fixes how percent symbols are handled in files, fixes quick tips showing %%, and adds memory debug information to the FPS debug display. | Official notes |
| Aug 5, 2026 | 42.20.1 STABLE Hotfix Released | This stable hotfix improves multiplayer performance and anti-cheat checks, fixes a memory leak and several crashes, and lets mods write .json files. | Official notes |
| Jul 29, 2026 | Build 42.20.0 Stable Released | Official notes | |
| Jul 27, 2026 | 42.20: The Big Glow Up | Official notes | |
| Jun 1, 2026 | Build 42.19.0 Unstable Released | Official notes | |
| May 11, 2026 | Build 42.18.0 Unstable Released | Official notes | |
| Apr 20, 2026 | Build 42.17.0 Unstable Released | Official notes | |
| Apr 8, 2026 | Stable(41.78.19) + UNSTABLE(42.16.3) Hotfixes Released | Official notes |
How often does Project Zomboid get updated?
Project Zomboid has had 8 patch announcements on Steam in the last 90 days and 24 in the past year, roughly one every 15 days.
Project Zomboid patch notes FAQ
When was the last Project Zomboid update?
The most recent Project Zomboid update is "Build 42.21 Stable Released", posted on Steam on Sep 28, 2026.
What changed in the latest Project Zomboid patch?
Build 42.21 is released to Stable after a week in the Unstable beta, where the community reported no major issues. It addresses the worst zombie duplication and disappearing zombie bugs, and changes how XXL trees cut away. The loadstring and loadstream Lua methods are enabled again.
How often does Project Zomboid get patched?
Project Zomboid has had 8 patch announcements on Steam in the last 90 days and 24 in the past year, roughly one every 15 days.
Where can I read the official Project Zomboid patch notes?
The developer posts full patch notes on the game's Steam news page. We link each one in the table above.
More on Project Zomboid
- Project Zomboid stats, news and reviews
- Project Zomboid player count: is it dead?
- Is Project Zomboid cross platform?
- Project Zomboid news on Steam
How we write these: Explosion summarizes the developer’s official Steam announcements and links the original notes. This page checks for new patches several times a day.
Nick Guli
Nick Guli is the founder and editor-in-chief of Explosion.com, which he launched in February 2012. With over a decade of experience in digital publishing, Nick oversees editorial direction across entertainment, gaming, technology, and lifestyle content. He is an avid gamer and movie enthusiast who brings a critical eye to coverage of industry trends, game reviews, and entertainment news.
