CVE-2026-12866
criticalpriority · track · 0EPSS 0.009 · 59 %ileEUUSEPSS · scored 2026-10-27
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
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · high–critical · 7.2–9.8
ssvc
A stakeholder decision — act, attend, or track — from exploitation and impact.
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (4)
Products and version ranges known to be affected.
advisories (1)
Vendor and ecosystem advisories describing this.
- GHSA-q9v2-7m5w-4693expr-eval vulnerable to Code Execution2026-06-23ghsa · osvUS
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.
also known as (3)
Other names and identifiers for this entity.
sources
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references (11)
External citations — patches, advisories, analysis.
- https://github.com/silentmatt/expr-eval/blob/master/src/expression.js%23L55cnnvd
- https://github.com/silentmatt/expr-eval/issues/292cnnvd
- https://security.snyk.io/vuln/SNYK-JS-EXPREVAL-15054690cnnvd
- https://github.com/silentmatt/expr-eval/blob/master/src/expression.js%23L55enisa_euvd
- https://github.com/silentmatt/expr-eval/issues/292enisa_euvd
- https://security.snyk.io/vuln/SNYK-JAVA-ORGWEBJARSNPM-17662018enisa_euvd
- https://security.snyk.io/vuln/SNYK-JS-EXPREVAL-15054690enisa_euvd
- https://github.com/silentmatt/expr-eval/blob/master/src/expression.js%23L55nvd
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