🚨 HIGH - Bash construct permission splitter bypass in rtk (CVE-2026-54555) rtk before 0.42.2 contains a flaw in its permission splitter logic that fails to conservatively split or reject certain Bash shell constructs that create command-execution boundaries or nested execution, allowing a permitted prefix like “git” to mask an additional command. The root cause is improper input validation/parsing of shell syntax, leading to command injection via ambiguous or nested Bash constructs. An attacker can exploit this by crafting a command line that starts with an allowed command but embeds a second command inside a construct that the splitter mishandles, so rtk rewrite returns exit code 0 and an allow decision while the hidden command still runs without intended user confirmation. Impact includes unauthorized command execution under the user’s context, enabling data theft, persistence actions, or destructive operations depending on what the hidden command does. 👉 Affected: rtk < 0.42.2 | Upgrade to 0.42.2
Post summary
The post warns that rtk versions prior to 0.42.2 contain a Bash‑based command injection flaw and advises users to upgrade to 0.42.2 for remediation.