{"id":"CVE-2026-82750","title":"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 de…","summary":"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 de…","severity":"high","cvss":8.3,"cvssVector":"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","cwe":["CWE-1284"],"vendor":"ZenHive","product":"mpp","affected":["mpp >= 0.2.0 < 0.16.1","zenhive/mpp >= d29d54e507918db00a5b65d90136b73166c017d7 < 0482572b47e1ffe1537ab80ab613d47b92833c2d"],"published":"2026-09-06","updated":"2026-09-08","sourceUpdated":"2026-09-08T19:20:01.200","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-82750","references":[{"url":"https://cna.erlef.org/cves/CVE-2026-82750.html","label":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db"},{"url":"https://github.com/ZenHive/mpp/commit/0482572b47e1ffe1537ab80ab613d47b92833c2d","label":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db"},{"url":"https://github.com/ZenHive/mpp/security/advisories/GHSA-5qrp-r24c-w6jr","label":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db"},{"url":"https://osv.dev/vulnerability/EEF-CVE-2026-82750","label":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db"}],"tags":["nvd","cve.org"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2026-09-08T18:25:27.116993Z"},"cvssSource":"cna","epss":0.00524,"epssPercentile":0.42003,"ingestedAt":"2026-09-07T06:06:09.643Z","slug":"CVE-2026-82750","body":"## Overview\n\nImproper 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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":46,"depthScoreParts":{"impact":45.7,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[{"seq":8263,"id":"CVE-2026-82750","ts":1788919995216,"field":"cvss","old":null,"new":"8.3"},{"seq":8262,"id":"CVE-2026-82750","ts":1788919995216,"field":"severity","old":"none","new":"high"},{"seq":8072,"id":"CVE-2026-82750","ts":1788919281082,"field":"cvss","old":"8.3","new":null},{"seq":8071,"id":"CVE-2026-82750","ts":1788919281082,"field":"severity","old":"high","new":"none"},{"seq":7881,"id":"CVE-2026-82750","ts":1788916356296,"field":"cvss","old":null,"new":"8.3"},{"seq":7880,"id":"CVE-2026-82750","ts":1788916356296,"field":"severity","old":"none","new":"high"},{"seq":7690,"id":"CVE-2026-82750","ts":1788915297782,"field":"cvss","old":"8.3","new":null},{"seq":7689,"id":"CVE-2026-82750","ts":1788915297782,"field":"severity","old":"high","new":"none"},{"seq":7499,"id":"CVE-2026-82750","ts":1788912716939,"field":"cvss","old":null,"new":"8.3"},{"seq":7498,"id":"CVE-2026-82750","ts":1788912716939,"field":"severity","old":"none","new":"high"},{"seq":7308,"id":"CVE-2026-82750","ts":1788911331726,"field":"cvss","old":"8.3","new":null},{"seq":7307,"id":"CVE-2026-82750","ts":1788911331726,"field":"severity","old":"high","new":"none"},{"seq":7112,"id":"CVE-2026-82750","ts":1788909078571,"field":"cvss","old":null,"new":"8.3"},{"seq":7111,"id":"CVE-2026-82750","ts":1788909078571,"field":"severity","old":"none","new":"high"},{"seq":6924,"id":"CVE-2026-82750","ts":1788907391809,"field":"cvss","old":"8.3","new":null},{"seq":6923,"id":"CVE-2026-82750","ts":1788907391809,"field":"severity","old":"high","new":"none"},{"seq":6726,"id":"CVE-2026-82750","ts":1788905444499,"field":"cvss","old":null,"new":"8.3"},{"seq":6725,"id":"CVE-2026-82750","ts":1788905444499,"field":"severity","old":"none","new":"high"},{"seq":6544,"id":"CVE-2026-82750","ts":1788903460022,"field":"cvss","old":"8.3","new":null},{"seq":6543,"id":"CVE-2026-82750","ts":1788903460022,"field":"severity","old":"high","new":"none"},{"seq":6330,"id":"CVE-2026-82750","ts":1788901810851,"field":"cvss","old":null,"new":"8.3"},{"seq":6329,"id":"CVE-2026-82750","ts":1788901810851,"field":"severity","old":"none","new":"high"},{"seq":6160,"id":"CVE-2026-82750","ts":1788899562415,"field":"cvss","old":"8.3","new":null},{"seq":6159,"id":"CVE-2026-82750","ts":1788899562415,"field":"severity","old":"high","new":"none"},{"seq":5953,"id":"CVE-2026-82750","ts":1788898180042,"field":"cvss","old":null,"new":"8.3"},{"seq":5952,"id":"CVE-2026-82750","ts":1788898180042,"field":"severity","old":"none","new":"high"},{"seq":5842,"id":"CVE-2026-82750","ts":1788895711369,"field":"cvss","old":"8.3","new":null},{"seq":5841,"id":"CVE-2026-82750","ts":1788895711369,"field":"severity","old":"high","new":"none"},{"seq":5758,"id":"CVE-2026-82750","ts":1788894572981,"field":"cvss","old":null,"new":"8.3"},{"seq":5757,"id":"CVE-2026-82750","ts":1788894572981,"field":"severity","old":"none","new":"high"}]}