{"id":"EEF-CVE-2026-59252","summary":"Missing gas_limit validation in mpp Tempo fee-payer enables wallet drain","details":"## Summary\n\nImproper Validation of Specified Quantity in Input in ZenHive mpp allows an unauthenticated remote client to drain the fee-payer wallet, resulting in denial of service for legitimate clients.\n\nWhen the mpp Elixir library is configured as fee payer (fee\\_payer: true), the MPP.Methods.Tempo payment method co-signs and broadcasts a client-supplied EVM transaction without first validating that the client-supplied gas\\_limit is sufficient to complete the intended call. A malicious client can submit a signed transferWithMemo transaction with gas\\_limit deliberately set just below the amount required for successful execution. The server co-signs the transaction and broadcasts it via rpc\\_broadcast\\_sync. The transaction runs out of gas during EVM execution and reverts, but the fee-payer wallet is still charged for the burned gas while the client pays nothing and receives no resource. Repeated requests from one or more malicious clients drain the fee-payer wallet at near-zero cost to the attacker, ultimately preventing the server from sponsoring gas for legitimate payment requests.\n\nThe wait\\_for\\_confirmation = false (optimistic) path is also affected: it invokes simulate\\_payment\\_call via eth\\_call, but that simulation omits the gas parameter and therefore does not catch out-of-gas conditions.\n\nThis issue affects mpp: from 0.2.0 before 0.6.0.\n\n## Configuration\n\nThe vulnerable code path is only reachable when the MPP.Methods.Tempo method is configured with fee\\_payer: true (server-side gas sponsorship). Default deployments with fee\\_payer: false are not affected, since the client pays for gas out of its own wallet.","aliases":["CVE-2026-59252","GHSA-vj8p-hp9x-gh47"],"modified":"2026-07-18T04:12:42.459Z","published":"2026-07-17T10:11:54.436Z","database_specific":{"cpe_ids":["cpe:2.3:a:ZenHive:mpp:*:*:*:*:*:*:*:*"],"cwe_ids":["CWE-1284"],"capec_ids":["CAPEC-130"]},"references":[{"type":"ADVISORY","url":"https://github.com/ZenHive/mpp/security/advisories/GHSA-vj8p-hp9x-gh47"},{"type":"WEB","url":"https://cna.erlef.org/cves/CVE-2026-59252.html"},{"type":"FIX","url":"https://github.com/ZenHive/mpp/commit/d84e3e528db39654540c2035ea0fbdf7b950d3d1"},{"type":"PACKAGE","url":"https://hex.pm/packages/mpp"}],"affected":[{"package":{"name":"mpp","ecosystem":"Hex","purl":"pkg:hex/mpp"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0.2.0"},{"fixed":"0.6.0"}]}],"versions":["0.2.0","0.3.0","0.3.1","0.3.2","0.4.0"],"database_specific":{"source":"https://cna.erlef.org/osv/EEF-CVE-2026-59252.json"}},{"ranges":[{"type":"GIT","repo":"https://github.com/ZenHive/mpp","events":[{"introduced":"d29d54e507918db00a5b65d90136b73166c017d7"},{"fixed":"d84e3e528db39654540c2035ea0fbdf7b950d3d1"}]}],"versions":["v0.5.1","v0.4.0","v0.3.0","v0.2.0"],"database_specific":{"source":"https://cna.erlef.org/osv/EEF-CVE-2026-59252.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N"}],"credits":[{"name":"Kian Kai Ang","type":"FINDER"},{"name":"E.FU","type":"REMEDIATION_DEVELOPER"},{"name":"Jonatan Männchen / EEF","type":"ANALYST"}]}