← Vulnerability feed

Vulnerability record · CVE-2026-12866 · published 23 June 2026

CVE-2026-12866: Code injection vulnerability

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.

9.2 CVSS 4.0 Critical EPSS 0.87% · top 43.0% CWE-94 · Code injection Deferred
9.2CVSS 4.0 base score
0.87%EPSS exploitation probability, 30 days
NoNot in CISA KEV
0Affected product versions listed by NVD
5References
7 Jul 2026Last modified by NVD

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: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:

References

LinkTags
https://github.com/silentmatt/expr-eval/blob/master/src/expression.js%23L55
https://github.com/silentmatt/expr-eval/issues/292
https://security.snyk.io/vuln/SNYK-JAVA-ORGWEBJARSNPM-17662018
https://security.snyk.io/vuln/SNYK-JS-EXPREVAL-15054690
https://security.snyk.io/vuln/SNYK-JS-EXPREVAL-15054690

Track CVE-2026-12866 inside VULONE

Watch it alongside the ransomware crews, C2 infrastructure and forum chatter that reference it, query it through the API and pull it into your SIEM over TAXII.

Start free Open in platform

Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

8.8CVE-2026-65660Microsoft sharepoint server code injection vulnerabilityImproper control of generation of code ('code injection') in Microsoft Office SharePoint allows an authorized attacker to execute code over a network.KEVEPSS 2.1%9.8CVE-2026-60004Gitea diffpatch API code injection enables remote code executionGitea before 1.27.1 allows remote code execution through the diffpatch API by way of Git hook installation. The flaw is a code injection issue (CWE-9…KEVEPSS 24%analysed9.5CVE-2026-72530TrueConf Server sandbox breakout via crafted script code injectionTrueConf Server versions 5.3.X through 5.3.9, 5.4.X through 5.4.9, 5.5.X through 5.5.5 and earlier allow a remote unauthenticated attacker to break o…KEVEPSS 1.7%analysed9.4CVE-2025-62593Ray browser-based RCE via insufficient User-Agent guardRay, an AI compute engine, contains a critical remote code execution flaw before version 2.52.0. Its defense against browser-based attacks relies on …KEVEPSS 62%analysed9.8CVE-2026-9198Langflow auto_login and code validation chain enables unauthenticated RCEIBM Langflow OSS 1.0.0 through 1.10.0 exposes /api/v1/auto_login, which mints SUPERUSER tokens to any network caller, and /api/v1/validate/code, whic…KEVEPSS 29%analysed7.2CVE-2026-15410SonicWall SMA1000 AMC code injection allows OS command executionThe SMA1000 Appliance Management Console (AMC) contains a post-authentication code injection flaw (CWE-94) that, under specific conditions, lets an a…KEVEPSS 12%analysed9.8CVE-2008-4250Microsoft Windows Server service RPC path canonicalization buffer overflowThe Server service in multiple Windows versions fails to properly handle path canonicalization, allowing a crafted RPC request to overflow a buffer a…KEVEPSS 99%analysed8.8CVE-2026-34197Apache ActiveMQ Jolokia JMX bridge code injection via broker config URIApache ActiveMQ Classic exposes the Jolokia JMX-HTTP bridge at /api/jolokia/ with a default policy that allows exec operations on all org.apache.acti…KEVEPSS 15%analysed

Source: NIST National Vulnerability Database (record CVE-2026-12866), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.