THE SHORT ANSWER
Minecraft Java Edition 26.1.2 Release Candidate 1 arrived April 8, 2026, fixing UI checkbox behavior and an exploit; it carries data version 4789 and is the only RC planned before the hotfix goes live.
- Released April 8, 2026 as 26.1.2-rc-1; first and only release candidate for the 26.1.2 hotfix.
- Addresses UI checkbox rendering and a previously undisclosed exploit.
- Data version 4789, protocol version 1073742131, data pack format 101.1, resource pack format 84.0.
- Remains compatible with existing 26.1 worlds and servers.
- Full 26.1.2 release expected soon if no further critical issues surface.
What shipped
Mojang published the first and only release candidate for Java Edition 26.1.2 on April 8, 2026. The build, labeled 26.1.2-rc-1 in the launcher, is a targeted hotfix rather than a feature update. Its scope is narrow: correct UI checkbox behavior and close an exploit that surfaced after the 26.1 launch.
Technical identifiers
- Data version: 4789
- Protocol version: 1073742131
- Data pack format: 101.1
- Resource pack format: 84.0
These numbers matter for server operators and add-on authors. The protocol bump means 26.1.2 clients will not connect to older 26.1 servers until those servers update, but the data pack and resource pack formats are backward compatible with 26.1 content.
Fixes in detail
The changelog highlights two categories:
UI checkboxes – Checkbox widgets in menus and settings screens were not rendering their checked/unchecked state consistently across resolutions and scaling settings. The fix restores the expected visual feedback.
Exploit mitigation – Mojang has not disclosed the exact nature of the exploit, consistent with their practice of withholding details until the majority of players have updated. The fix is server-side compatible, meaning a patched client connecting to an unpatched server (or vice versa) will not trigger the vulnerability.
Compatibility
Worlds created in 26.1 load without conversion. Servers running 26.1.2 accept connections from 26.1 clients once the server updates, but 26.1.2 clients require a 26.1.2 server. Realms and dedicated server hosts typically roll out the new jar within hours of the full release.
What happens next
If the community and internal QA find no regressions in this candidate, Mojang will promote the same build to the stable 26.1.2 channel — usually within 24 to 48 hours. No further release candidates are planned. Players on the snapshot track can switch back to the stable channel once the hotfix goes live; no world migration is needed.