CVE-2026-81097

Name of the Vulnerable Software and Affected Versions Software versions 1.4.0 through 1.6.0

Description The execute ruby tool, designed as a read-only Ruby sandbox, uses a pattern denylist and replacements for process-spawning methods on Kernel to restrict execution. However, spawn entry points within the pseudo-terminal library are not included in the denylist or replaced. This allows a tool call to access these entry points and start a shell, enabling the execution of commands as the account running the server, bypassing the guarded methods.

Recommendations Update to version 1.6.1 to restrict permitted requires to a data-only list and block dynamic dispatch to execution entry points. Update to version 2.0.0 to remove the tool entirely.