CVE-2026-12866
CRITICAL
9.8
Our Analysis: Environment Specific
Our model has classified this vulnerability as relevant to Environment Specific Systems, helping your team prioritize efforts effectively.
Published Date
June 23, 2026
Last Modified
June 23, 2026
CVSS Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Description
All versions of the package expr-eval are vulnerable to Code Execution via the toJSFunction() API. An attacker can execute arbitrary JavaScript by supplying crafted expressions that are compiled into native code using new Function(). Because user-controlled expressions are transformed directly into executable JavaScript, attackers can escape the intended expression sandbox and run arbitrary code within the application's context.