CVE-2026-82750

Status: DeferredHigh (8.3)—

Improper Validation of Specified Quantity in Input in ZenHive mpp allows an unauthenticated remote client to inflate the fee-payer's gas cost per sponsored payment by a large multiplier and to have the sponsor pay for EIP-7702 account delegations of the client's choosing.

When the server sponsors Tempo payments, MPP.Methods.Tempo.FeePayerPolicy.measure/3 in lib/mpp/methods/tempo/fee_payer_policy.ex bounds the gas fields, the fee budget, the validity window and the access list of the client-signed 0x76 envelope, but never reads its aa_authorization_list field.

Read full descriptionShow less

Every signed delegation in that list is charged as intrinsic gas before the payment call runs, so a client attaching delegations from throwaway authority keys makes the sponsor pay for them within the default gas_limit ceiling. At the reporter's default of seven entries the sponsored cost rises from about 46,575 gas to about 1,884,087 gas. Because each entry is applied as a persistent set-code delegation, a client can also upgrade its own accounts to delegated code at the sponsor's expense.

This issue affects mpp: from 0.2.0 before 0.16.1.

CVSS

Version: 4.0
Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:L/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
Base score: 8.3

Exploitation probability (EPSS)

Probability of exploitation in the next 30 days: 0.52%
Percentile among all scored CVEs: 43
Score date: 10/6/2026

EPSS (Exploit Prediction Scoring System, FIRST) estimates how likely a vulnerability is to be exploited in the wild within 30 days. It complements CVSS (impact) and CISA KEV (confirmed exploitation).

🎯 ATT&CK techniques

How this vulnerability is exploited and what the attacker gains, in MITRE ATT&CK terms.

ExploitationT1190 Exploit Public-Facing Applicationinitial access85 %
Primary impactT1499.004 Application or System Exploitationimpact80 %
Secondary impactT1565.001 Stored Data Manipulationimpact75 %

Validación impropia de cantidad en entrada remota permite cliente no autenticado inflar costos de gas del patrocinador mediante lista aa_authorization_list no validada, causando DoS económico y manipulación de datos de delegación EIP-7702.

Inferred by our analysis agent from the official description, CVSS vector and CWE, and checked by a supervisor. May contain errors.

🛡️ ATT&CK mitigations that cover these techniques

Filter Network Traffic Vulnerability Scanning Restrict File and Directory Permissions Privileged Account Management Remote Data Storage Network Segmentation

Affected technologies (1)

⚠ AI-inferred from the description — NVD hasn't analyzed this CVE yet, these aren't verified CPEs.

Zenhive — MPP^AI

CWEs

CWE-1284

References

Raw JSON (NVD)

Show

{
  "id": "CVE-2026-82750",
  "cveTags": [],
  "metrics": {
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      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-82750",
          "role": "CISA Coordinator",
          "options": [
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              "automatable": "no"
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          "version": "2.0.3",
          "timestamp": "2026-09-08T18:25:27.116993Z"
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          "attackVector": "NETWORK",
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          "valueDensity": "NOT_DEFINED",
          "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:L/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",
          "exploitMaturity": "NOT_DEFINED",
          "providerUrgency": "NOT_DEFINED",
          "userInteraction": "NONE",
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          "subIntegrityImpact": "NONE",
          "vulnIntegrityImpact": "HIGH",
          "integrityRequirement": "NOT_DEFINED",
          "modifiedAttackVector": "NOT_DEFINED",
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          "availabilityRequirement": "NOT_DEFINED",
          "modifiedUserInteraction": "NOT_DEFINED",
          "modifiedAttackComplexity": "NOT_DEFINED",
          "subConfidentialityImpact": "NONE",
          "vulnConfidentialityImpact": "NONE",
          "confidentialityRequirement": "NOT_DEFINED",
          "modifiedAttackRequirements": "NOT_DEFINED",
          "modifiedPrivilegesRequired": "NOT_DEFINED",
          "modifiedSubIntegrityImpact": "NOT_DEFINED",
          "modifiedVulnIntegrityImpact": "NOT_DEFINED",
          "vulnerabilityResponseEffort": "NOT_DEFINED",
          "modifiedSubAvailabilityImpact": "NOT_DEFINED",
          "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
          "modifiedSubConfidentialityImpact": "NOT_DEFINED",
          "modifiedVulnConfidentialityImpact": "NOT_DEFINED"
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  "affected": [
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      "affectedData": [
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          "cpes": [
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          "vendor": "ZenHive",
          "modules": [
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            "'Elixir.MPP.Methods.Tempo'"
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        {
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            {
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  ],
  "published": "2026-09-06T17:17:55.867",
  "references": [
    {
      "url": "https://cna.erlef.org/cves/CVE-2026-82750.html",
      "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db"
    },
    {
      "url": "https://github.com/ZenHive/mpp/commit/0482572b47e1ffe1537ab80ab613d47b92833c2d",
      "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db"
    },
    {
      "url": "https://github.com/ZenHive/mpp/security/advisories/GHSA-5qrp-r24c-w6jr",
      "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db"
    },
    {
      "url": "https://osv.dev/vulnerability/EEF-CVE-2026-82750",
      "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db"
    }
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  "vulnStatus": "Deferred",
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      "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
      "description": [
        {
          "lang": "en",
          "value": "CWE-1284"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "Improper Validation of Specified Quantity in Input in ZenHive mpp allows an unauthenticated remote client to inflate the fee-payer's gas cost per sponsored payment by a large multiplier and to have the sponsor pay for EIP-7702 account delegations of the client's choosing.\n\nWhen the server sponsors Tempo payments, MPP.Methods.Tempo.FeePayerPolicy.measure/3 in lib/mpp/methods/tempo/fee_payer_policy.ex bounds the gas fields, the fee budget, the validity window and the access list of the client-signed 0x76 envelope, but never reads its aa_authorization_list field. Every signed delegation in that list is charged as intrinsic gas before the payment call runs, so a client attaching delegations from throwaway authority keys makes the sponsor pay for them within the default gas_limit ceiling. At the reporter's default of seven entries the sponsored cost rises from about 46,575 gas to about 1,884,087 gas. Because each entry is applied as a persistent set-code delegation, a client can also upgrade its own accounts to delegated code at the sponsor's expense.\n\nThis issue affects mpp: from 0.2.0 before 0.16.1."
    }
  ],
  "lastModified": "2026-09-08T19:20:01.200",
  "sourceIdentifier": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db"
}