CVE-2026-12866
CRITICAL EPSS 36.2%
Published Jun 23, 20261w ago · Modified Jun 23, 20261w ago
9.2 CVSS 4.0
Published Jun 23, 2026 1w ago
Last Modified Jun 23, 2026 1w ago
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.
CVSS Details
Base Score
Exploitability
Impact
Vector string
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction None
Scope X
Threat Intelligence
EPSS Exploit Probability
36.2% percentile
Exploit & Patch Status
No Known Exploit
No Patch Available
Weaknesses 1
CWE-94 Improper Control of Generation of Code (Code Injection) Injection
References 3
- github.com https://github.com/silentmatt/expr-eval/blob/master/src/expression.js%23L55
- github.com https://github.com/silentmatt/expr-eval/issues/292
- security.snyk.io https://security.snyk.io/vuln/SNYK-JS-EXPREVAL-15054690
Remediation
No remediation data recorded yet
Check vendor advisories and the NVD entry for patch availability.