CVE-2026-81097

What it is

The execute_ruby tool is documented as a read-only Ruby sandbox and is enforced by a pattern denylist together with replacements for the process-spawning methods on Kernel. The pseudo-terminal library's spawn entry points are neither in the denylist nor replaced, so a normal tool call could reach them and start a shell, executing commands as the account running the server and outside the guarded methods. The denylist was introduced with the tool in 1.4.0 and never covered those entry points through 1.6.0. Version 1.6.1 restricts the requires the sandbox permits to a data-only list and blocks dynamic dispatch to execution entry points; 2.0.0 removes the tool.

At a glance

Exploitability

Can be exploited locally on the machine without logging in. High risk of data exposure, data tampering, service disruption.

Exploit odds

0.2% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2026-08-27 17:20 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-09-24 20:43 UTC Last updatedMost recent change to the record

Details

Published

2026-08-27 17:20 UTC

Last modified

2026-09-24 20:43 UTC

Exploit probability

0.2% · EPSS, next 30 days

Weakness

CWE-78 · OS command injection

Record status

Deferred

Attack profile CVSS 4.0 · 8.6

Attack vector

Local

Complexity

Low

Attack requirements

None

Privileges needed

None

User interaction

None

Confidentiality

High

Integrity

High

Availability

High