Claude Code 2.1.299 blocks a sandbox write path into reloadable plugins.
The patch closes a path through which a sandboxed shell command could write into a --plugin-dir folder. Claude Code reloads that code and runs it outside the sandbox. The release also fixes a mod that could keep a headless run going beyond its turn or dollar limit. Both fixes are in 2.1.299, published at 02:49 UTC. 1
Check both the plugin write boundary and the stop condition. Upgrade affected installations before running another unattended task with reloadable plugins. In a disposable setup, try a sandboxed write to the plugin directory and confirm that a turn-ending mod stops at the configured limit.
The vendor notes establish the repaired paths. They do not establish whether a particular deployment was exploited or whether every plugin is safe. Keep plugin source directories outside the writable task area and preserve the version with the test result.
Upgrade, then check the plugin write boundary and the headless stop condition.