CWE-1321
AllowedImproperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')
Abstraction: Variant · Status: Incomplete
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.
782 vulnerabilities reference this CWE, most recent first.
GHSA-XX4G-R65P-3QF2
Vulnerability from github – Published: 2025-09-24 21:30 – Updated: 2025-09-25 19:28mpregular is a package that provides a small program development framework based on RegularJS. A Prototype Pollution vulnerability in the mp.addEventHandler function of mpregular version 0.2.0 and before allows attackers to inject properties on Object.prototype via supplying a crafted payload, causing denial of service (DoS) as the minimum consequence.
{
"affected": [
{
"package": {
"ecosystem": "npm",
"name": "mpregular"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"last_affected": "0.2.0"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2025-57323"
],
"database_specific": {
"cwe_ids": [
"CWE-1321"
],
"github_reviewed": true,
"github_reviewed_at": "2025-09-25T19:28:53Z",
"nvd_published_at": "2025-09-24T20:15:32Z",
"severity": "HIGH"
},
"details": "mpregular is a package that provides a small program development framework based on RegularJS. A Prototype Pollution vulnerability in the mp.addEventHandler function of mpregular version 0.2.0 and before allows attackers to inject properties on Object.prototype via supplying a crafted payload, causing denial of service (DoS) as the minimum consequence.",
"id": "GHSA-xx4g-r65p-3qf2",
"modified": "2025-09-25T19:28:53Z",
"published": "2025-09-24T21:30:37Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-57323"
},
{
"type": "WEB",
"url": "https://github.com/VulnSageAgent/PoCs/blob/main/JavaScript/prototype-pollution/mpregular%400.2.0/index.js"
},
{
"type": "WEB",
"url": "https://github.com/VulnSageAgent/PoCs/tree/main/JavaScript/prototype-pollution/CVE-2025-57323"
},
{
"type": "PACKAGE",
"url": "https://github.com/regularjs/regular"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
],
"summary": "mpregular vulnerable to prototype pollution"
}
GHSA-XXJR-MMJV-4GPG
Vulnerability from github – Published: 2026-01-21 23:01 – Updated: 2026-06-09 10:56Impact
Lodash versions 4.0.0 through 4.17.22 are vulnerable to prototype pollution in the _.unset and _.omit functions. An attacker can pass crafted paths which cause Lodash to delete methods from global prototypes.
The issue permits deletion of properties but does not allow overwriting their original behavior.
Patches
This issue is patched on 4.17.23.
{
"affected": [
{
"database_specific": {
"last_known_affected_version_range": "\u003c= 4.17.22"
},
"package": {
"ecosystem": "npm",
"name": "lodash"
},
"ranges": [
{
"events": [
{
"introduced": "4.0.0"
},
{
"fixed": "4.17.23"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "npm",
"name": "lodash.unset"
},
"ranges": [
{
"events": [
{
"introduced": "4.0.0"
},
{
"last_affected": "4.5.2"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"database_specific": {
"last_known_affected_version_range": "\u003c= 4.17.22"
},
"package": {
"ecosystem": "npm",
"name": "lodash-es"
},
"ranges": [
{
"events": [
{
"introduced": "4.0.0"
},
{
"fixed": "4.17.23"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"database_specific": {
"last_known_affected_version_range": "\u003c= 4.17.22"
},
"package": {
"ecosystem": "npm",
"name": "lodash-amd"
},
"ranges": [
{
"events": [
{
"introduced": "4.0.0"
},
{
"fixed": "4.17.23"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2025-13465"
],
"database_specific": {
"cwe_ids": [
"CWE-1321"
],
"github_reviewed": true,
"github_reviewed_at": "2026-01-21T23:01:22Z",
"nvd_published_at": "2026-01-21T20:16:05Z",
"severity": "MODERATE"
},
"details": "### Impact\n\nLodash versions 4.0.0 through 4.17.22 are vulnerable to prototype pollution in the `_.unset` and `_.omit` functions. An attacker can pass crafted paths which cause Lodash to delete methods from global prototypes. \n\nThe issue permits deletion of properties but does not allow overwriting their original behavior. \n\n### Patches\n\nThis issue is patched on 4.17.23.",
"id": "GHSA-xxjr-mmjv-4gpg",
"modified": "2026-06-09T10:56:34Z",
"published": "2026-01-21T23:01:22Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/lodash/lodash/security/advisories/GHSA-xxjr-mmjv-4gpg"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-13465"
},
{
"type": "WEB",
"url": "https://github.com/lodash/lodash/commit/edadd452146f7e4bad4ea684e955708931d84d81"
},
{
"type": "WEB",
"url": "https://cert-portal.siemens.com/productcert/html/ssa-253495.html"
},
{
"type": "PACKAGE",
"url": "https://github.com/lodash/lodash"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L",
"type": "CVSS_V3"
},
{
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:L/SC:H/SI:H/SA:H/E:P",
"type": "CVSS_V4"
}
],
"summary": "Lodash has Prototype Pollution Vulnerability in `_.unset` and `_.omit` functions"
}
Mitigation
By freezing the object prototype first (for example, Object.freeze(Object.prototype)), modification of the prototype becomes impossible.
Mitigation
By blocking modifications of attributes that resolve to object prototype, such as proto or prototype, this weakness can be mitigated.
Mitigation
Strategy: Input Validation
When handling untrusted objects, validating using a schema can be used.
Mitigation
By using an object without prototypes (via Object.create(null) ), adding object prototype attributes by accessing the prototype via the special attributes becomes impossible, mitigating this weakness.
Mitigation
Map can be used instead of objects in most cases. If Map methods are used instead of object attributes, it is not possible to access the object prototype or modify it.
CAPEC-1: Accessing Functionality Not Properly Constrained by ACLs
In applications, particularly web applications, access to functionality is mitigated by an authorization framework. This framework maps Access Control Lists (ACLs) to elements of the application's functionality; particularly URL's for web apps. In the case that the administrator failed to specify an ACL for a particular element, an attacker may be able to access it with impunity. An attacker with the ability to access functionality not properly constrained by ACLs can obtain sensitive information and possibly compromise the entire application. Such an attacker can access resources that must be available only to users at a higher privilege level, can access management sections of the application, or can run queries for data that they otherwise not supposed to.
CAPEC-180: Exploiting Incorrectly Configured Access Control Security Levels
An attacker exploits a weakness in the configuration of access controls and is able to bypass the intended protection that these measures guard against and thereby obtain unauthorized access to the system or network. Sensitive functionality should always be protected with access controls. However configuring all but the most trivial access control systems can be very complicated and there are many opportunities for mistakes. If an attacker can learn of incorrectly configured access security settings, they may be able to exploit this in an attack.
CAPEC-77: Manipulating User-Controlled Variables
This attack targets user controlled variables (DEBUG=1, PHP Globals, and So Forth). An adversary can override variables leveraging user-supplied, untrusted query variables directly used on the application server without any data sanitization. In extreme cases, the adversary can change variables controlling the business logic of the application. For instance, in languages like PHP, a number of poorly set default configurations may allow the user to override variables.