CVE-2026-54555 — rtk: Permission-gate bypass in rtk rewrite auto-allow via unsplit shell separators
rtk filters and compresses command outputs before they reach your LLM context. Prior to 0.42.2, the permission splitter did not conservatively split or reject several shell cons…
Published: 2026-06-23 · CVSS: 7.8 · CVSS 3.1
rtk filters and compresses command outputs before they reach your LLM context. Prior to 0.42.2, the permission splitter did not conservatively split or reject several shell constructs that Bash treats as command execution boundaries or nested execution. As a result, a command beginning with an allowed prefix such as git could hide a second command behind one of these constructs. rtk rewrite returned exit code 0, causing the Claude hook to emit permissionDecision: "allow". The rewritten command still contained the hidden command, so it ran without the user confirmation or denial that the permission rules were intended to enforce. This vulnerability is fixed in 0.42.2.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7