CVE-2026-26021
EPSS 0.04%set-in Affected by Prototype Pollution
描述
### Summary A prototype pollution vulnerability exists in the the npm package set-in (>=2.0.1). Despite a previous fix that attempted to mitigate prototype pollution by checking whether user input contained a forbidden key, it is still possible to pollute Object.prototype via a crafted input using Array.prototype. This has been fixed in version 2.0.5. ### Details The vulnerability resides in line 28 of https://github.com/ahdinosaur/set-in/blob/master/index.js where includes() function is used to check whether user provided input contain forbidden strings. ### PoC #### Steps to reproduce 1. Install latest version of set-in using npm install or cloning from git 2. Run the following code snippet: ```javascript Array.prototype.includes = () => false; const si = require('set-in'); const obj = {}; console.log({}.polluted); si(obj, [ 'constructor', 'prototype', 'polluted' ], 'yes'); console.log('{ ' + obj.polluted + ', ' + 'yes' + ' }'); // prints yes -> indicating that the patch was bypassed and prototype pollution occurred ``` #### Expected behavior Prototype pollution should be prevented and {} should not gain new properties. This should be printed on the console: ``` undefined undefined OR throw an Error ``` #### Actual behavior Object.prototype is polluted This is printed on the console: ``` undefined yes ``` ### Impact This is a prototype pollution vulnerability, which can have severe security implications depending on how set-in is used by downstream applications. Any application that processes attacker-controlled input using this package may be affected. It could potentially lead to the following problems: 1. Authentication bypass 2. Denial of service 3. Remote code execution (if polluted property is passed to sinks like eval or child_process)
受影響套件(1)
- npm/set-in>= 2.0.1, < 2.0.5
CVSS 分數
| 來源 | 版本 | 嚴重程度 | 向量 |
|---|---|---|---|
| osv | CVSS 4.0 | — | CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H |
參考連結(8)
- ADVISORYhttps://nvd.nist.gov/vuln/detail/CVE-2026-26021
- PATCHhttps://github.com/ahdinosaur/set-in
- WEBhttps://github.com/ahdinosaur/set-in/commit/34842cc02de3fd65d6f8bd0b268347e7b390125b
- WEBhttps://github.com/ahdinosaur/set-in/commit/6bad255961d379e4b1f5fbc52ef9dc8420816f24
- WEBhttps://github.com/ahdinosaur/set-in/commit/b8e1dabfdbd35c8d604b6324e01d03f280256c3d
- WEBhttps://github.com/ahdinosaur/set-in/commit/d87c1a09fa2edb55cd76440a67d83d1cb828df11
- WEBhttps://github.com/ahdinosaur/set-in/pull/6
- WEBhttps://github.com/ahdinosaur/set-in/security/advisories/GHSA-2c4m-g7rx-63q7