Vulnerability Description
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.
CVSS Score
HIGH
Related Weaknesses (CWE)
References
- https://github.com/rtk-ai/rtk/security/advisories/GHSA-7gxq-fvfc-g327
- https://github.com/rtk-ai/rtk/security/advisories/GHSA-7gxq-fvfc-g327
FAQ
What is CVE-2026-54555?
CVE-2026-54555 is a vulnerability with a CVSS score of 7.8 (HIGH). 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...
How severe is CVE-2026-54555?
CVE-2026-54555 has been rated HIGH with a CVSS base score of 7.8/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-54555?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.