9.8
/ 10
CRITICAL
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.
AI Analysis
Code Execution vulnerability in expr-eval package via toJSFunction() API
Basic Information
ID
CVE-2026-12866
Source
snyk
Published
Jun 23, 2026 at 05:00
Affected Product
Vendor
silentmatt
Product
expr-eval
Affected Versions
n/a expr-eval 0
AI Assessment
AI Score
9.8 / 10
AI Severity
Critical
Vendor
silentmatt
Product
expr-eval