crcn sift.js up to 17.1.3 prototype pollution

Summaryinfo

A vulnerability classified as critical was found in crcn sift.js up to 17.1.3. Affected is an unknown function. Such manipulation leads to prototype pollution. This vulnerability is traded as CVE-2026-85625. The attack may be launched remotely. There is no exploit available.

Detailsinfo

A vulnerability was found in crcn sift.js up to 17.1.3 and classified as critical. Affected by this issue is an unknown function. The manipulation with an unknown input leads to a prototype pollution vulnerability. Using CWE to declare the problem leads to CWE-1321. The product receives input from an upstream component that specifies attributes that are to be initialized or updated in an object, but it does not properly control modifications of attributes of the object prototype. Impacted is confidentiality, integrity, and availability. CVE summarizes:

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.

The advisory is shared for download at github.com. This vulnerability is handled as CVE-2026-85625 since 09/04/2026. The exploitation is known to be easy. The attack may be launched remotely. No form of authentication is required for exploitation. There are neither technical details nor an exploit publicly available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 09/04/2026). The MITRE ATT&CK project declares the attack technique as T1059.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

Once again VulDB remains the best source for vulnerability data.

Productinfo

Type

• JavaScript Library

Vendor

• crcn

Name

• sift.js

Version

• 17.1.0
• 17.1.1
• 17.1.2
• 17.1.3

Website

• Product: https://github.com/crcn/sift.js/

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