{"answers":{"affected":"1 open source package ship an affected version, including mpp.","exploited":"There is no known exploitation of CVE-2026-82751 in the wild and no public exploit code.","fix":"Upgrade mpp to 0.16.1 or later.","what":"CVE-2026-82751 is a high-severity vulnerability in ZenHive mpp, published on 6 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2026-82751 and fix it if it is affected.\n\nWhat it is: CVE-2026-82751 is a high-severity vulnerability in ZenHive mpp, published on 6 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2026-82751 in the wild and no public exploit code.\n\nAffected packages and fixed versions:\n- mpp (Hex): affected from 0.2.0; fixed in 0.16.1\n\nTask:\n1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.\n2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.\n3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.\n4. Run the tests and summarise what changed and why.\n5. If nothing in the project is affected, say so and change nothing.\n\nReference: https://insights.sbomify.com/CVE-2026-82751/ (Markdown: https://insights.sbomify.com/CVE-2026-82751/index.md)","id":"CVE-2026-82751","markdown":"https://insights.sbomify.com/CVE-2026-82751/index.md","name":"CVE-2026-82751","record":{"aliases":["EEF-CVE-2026-82751","GHSA-6fjm-7mv9-c325","GHSA-rpwj-vrf7-4x36"],"analysis":{"component_type":"library","fix_type":"upgrade","impacts":["data_modify","denial_of_service"],"network_reachable":"yes","non_default_config":false,"product_category":"Elixir payment library","requires_auth":"none","summary":"Attackers can inflate sponsor gas costs and provision unauthorized access keys by bypassing validation in the Tempo fee-payer policy.","user_interaction":"not_required","vuln_class":"business_logic"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"EEF","cpe":[],"cvss":{"score":8.3,"severity":"high","source":"cna","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","version":"4.0"},"cwes":[{"id":"CWE-1284","name":"Improper Validation of Specified Quantity in Input"}],"description":"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 provisioning an access key on the client's own account.\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 does not check whether the envelope carries the optional key_authorization field. A client can attach a fully signed key authorization, provisioning a new access key with token spending limits on its own account, alongside the normal payment call. The key and each limit entry are persistent storage writes billed as intrinsic gas to the sponsor, bounded only by the gas_limit ceiling. At the reporter's default of one key with three token limits the sponsored cost rises from about 46,587 gas to about 1,808,700 gas, and the client keeps a valid access key it paid nothing for.\n\nThis issue affects mpp: from 0.2.0 before 0.16.1.","ecosystems":["Hex"],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"none_known"},"has_fix":true,"headline":"Unbounded key authorization in mpp Tempo fee-payer sponsorship inflates gas cost and sponsors access-key provisioning","id":"CVE-2026-82751","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":"Hex","product":null,"products":[],"type":"business_logic","year":"2026"},"n_packages":1,"n_references":4,"next":{"headline":"Ash string length constraints count graphemes, so a combining-mark string of any size passes max_length","id":"CVE-2026-82752"},"packages":[{"ecosystem":"Hex","fixed":["0.16.1"],"introduced":["0.2.0"],"last_affected":[],"package":"mpp","purl":"pkg:hex/mpp","source":"EEF-CVE-2026-82751"}],"prev":{"headline":"Denial of service in mpp","id":"CVE-2026-82750"},"products":["mpp"],"published":"2026-09-06","related":[],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"CC BY 4.0","name":"Erlang Ecosystem Foundation","prefix":"EEF"},{"class":"attribution","licence":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":"no","exploitation":"none","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-09-08","vendors":["ZenHive"]},"summary":"Attackers can inflate sponsor gas costs and provision unauthorized access keys by bypassing validation in the Tempo fee-payer policy.","url":"https://insights.sbomify.com/CVE-2026-82751/"}