Affected: OliveTin

OliveTin gives access to predefined shell commands from a web interface. In versions 3000.0.0 and prior, the template engine uses a single shared text/template.Template instance (tpl package-level variable in service/internal/tpl/templates.go) across all goroutines. Every action execution calls tpl.Parse(source) followed by t.Execute() on this shared instance with no synchronization. When two or more actions execute concurrently (which is the normal case — each ExecRequest spawns a goroutine), a race condition occurs: one goroutine's Parse overwrites the template tree while another goroutine is calling Execute, causing cross-user command contamination, Go runtime panic, and incorrect command execution. This issue has been resolved in version 3000.13.0.