{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "source": "REFERENCES"
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "0482572b47e1ffe1537ab80ab613d47b92833c2d"
            }
          ],
          "repo": "https://github.com/zenhive/mpp",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-5qrp-r24c-w6jr"
  ],
  "database_specific": {
    "cna_assigner": "EEF",
    "cwe_ids": [
      "CWE-1284"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/82xxx/CVE-2026-82750.json",
    "unresolved_ranges": [
      {
        "extracted_events": [
          {
            "introduced": "0.2.0"
          },
          {
            "fixed": "0.16.1"
          },
          {
            "introduced": "d29d54e507918db00a5b65d90136b73166c017d7"
          },
          {
            "fixed": "0482572b47e1ffe1537ab80ab613d47b92833c2d"
          }
        ],
        "source": "AFFECTED_FIELD"
      },
      {
        "extracted_events": [
          {
            "introduced": "0.2.0"
          },
          {
            "fixed": "0.16.1"
          }
        ],
        "source": "CPE_FIELD"
      },
      {
        "extracted_events": [
          {
            "introduced": "0.2.0"
          },
          {
            "fixed": "0.16.1"
          }
        ],
        "source": "DESCRIPTION"
      }
    ]
  },
  "details": "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.",
  "id": "CVE-2026-82750",
  "modified": "2026-09-10T03:30:51.512503608Z",
  "published": "2026-09-06T16:08:41.089Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://cna.erlef.org/cves/CVE-2026-82750.html"
    },
    {
      "type": "WEB",
      "url": "https://github.com"
    },
    {
      "type": "WEB",
      "url": "https://osv.dev/vulnerability/EEF-CVE-2026-82750"
    },
    {
      "type": "WEB",
      "url": "https://repo.hex.pm"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/82xxx/CVE-2026-82750.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/ZenHive/mpp/security/advisories/GHSA-5qrp-r24c-w6jr"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-82750"
    },
    {
      "type": "FIX",
      "url": "https://github.com/ZenHive/mpp/commit/0482572b47e1ffe1537ab80ab613d47b92833c2d"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/ZenHive/mpp"
    }
  ],
  "schema_version": "1.9.0",
  "severity": [
    {
      "score": "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",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Unbounded EIP-7702 authorization list in mpp Tempo fee-payer sponsorship inflates gas cost and sponsors account delegation"
}