Vulnerability record · CVE-2026-85625 · published 4 September 2026
CVE-2026-85625: Prototype pollution vulnerability
sift (sift.js) 17.1.3 enumerates query keys with for...in, which walks the object prototype chain, and dispatches any matched operator key including $where. The $where operation compiles a string value into a function using new Function unless CSP_ENABLED is set (not set by default). As a result, if a prototype-pollution primitive elsewhere in the process sets Object.prototype.$where to a malicious string, even benign filter calls such as sift({}) execute arbitrary JavaScript. Additionally, passing an untrusted query object containing a string $where directly to sift results in code execution under the default configuration.
Description
sift (sift.js) 17.1.3 enumerates query keys with for...in, which walks the object prototype chain, and dispatches any matched operator key including $where. The $where operation compiles a string value into a function using new Function unless CSP_ENABLED is set (not set by default). As a result, if a prototype-pollution primitive elsewhere in the process sets Object.prototype.$where to a malicious string, even benign filter calls such as sift({}) execute arbitrary JavaScript. Additionally, passing an untrusted query object containing a string $where directly to sift results in code execution under the default configuration.
CVSS:4.0/AV:N/AC:H/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
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Related vulnerabilities
Same products first, then exploited flaws of the same weakness class.
Source: NIST National Vulnerability Database (record CVE-2026-85625), CISA KEV, FIRST EPSS (scores of 2026-09-28). This page is refreshed as NVD updates the record.
