{"cve":"CVE-2026-12866","nvd":{"published":"2026-06-23T05:17:03.380","modified":"2026-07-07T19:16:51.120","status":"Deferred","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_v4":{"vector":"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","score":9.2},"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","score":9.8},"cwes":["CWE-94"],"references":["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"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:39:28.638635428+00:00"},"epss":{"cve":"CVE-2026-12866","score":0.00866,"percentile":0.58706,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-q9v2-7m5w-4693","url":"https://osv.dev/vulnerability/GHSA-q9v2-7m5w-4693","summary":"expr-eval vulnerable to Code Execution","modified":"2026-09-22T14:45:10.513483389Z","packages":[{"ecosystem":"npm","name":"expr-eval","purl":"pkg:npm/expr-eval","ranges":["<=2.0.2"],"fixed":[]},{"ecosystem":"Maven","name":"org.webjars.npm:expr-eval","purl":"pkg:maven/org.webjars.npm/expr-eval","ranges":["<=2.0.2"],"fixed":[]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}