1.18.1 is a minor update to Java Edition, released on December 10, 2021, which makes minor changes related to fog and fixes bugs.^[1] It is compatible with 1.18 servers.

Most importantly, this version fixes a zero-day security vulnerability in the Log4j library that could be used to perform a remote code execution exploit. As a result, players were urged to secure their clients and servers.^[2]

While this wasn’t the last update to 1.18, it was the last one before the development versions of 1.19 started.

Changes

General

Fog

• World fog now starts farther away from the player, to make distant terrain more visible.
• Instead of applying fog as a spherical volume, it is now applied as a cylindrical volume.

Fixes

8 issues fixed

From released versions before 1.18

• MC-152198 – Actual render distance is 2 chunks lower than render distance setting.
• MC-219507 – Beacon's power reverts back to previous one on world reload.

From 1.18

• MC-242729 – Observer activating without any updates nearby, caused by /clone.
• MC-243216 – Chunk render distance on servers seems shorter than in 1.17.1.
• MC-243253 – Minecraft Realms screen is loading for long time.
• MC-243796 – Random non fatal exceptions in console: Failed to store chunk ConcurrentModificationException.

Other

• Fixed an issue that would cause players on low-bandwidth connections to get timeout errors when connecting to a server. ^[3]
• Fixed a critical security issue in which attackers are able to execute code on others' devices (RCE exploit) via in-game messaging or other methods where the game logs a certain exploitable string formatted as ${jndi:ldap://<url>}, due to an upstream vulnerability in log4j2. ^[4][2][5]

Trivia

• This was the last full version to be released in 2021.
• This is first time that minor updates received more than 2 release candidates.
• This version came out exactly 2 years after 1.15.
• This version came out after the final release candidate.

Videos

Videos made by slicedlime:

References