CVE-2026-87119

mpp · Vulnerability

CVSS 4.0 8.2 HIGHCheck source for fixed versionsKEV status unknown

Original advisory

cve-program · CVE-2026-87119

Published

Authentication Bypass by Capture-replay in ZenHive mpp allows an attacker holding a captured subscription activation credential to charge the payer repeatedly. The payer signs a Tempo KeyAuthorization over the chain id, key type, key id, expiry, limits and scopes only, with nothing tying it to the challenge that prompted it. MPP.Methods.Tempo.KeyAuthorization.verify/3 in lib/mpp/methods/tempo/key_authorization.ex pins each of those signed fields against the subscription request, and the access key it pins is a static per-endpoint server key, so one signed authorization verifies against every challenge the server issues for the same subscription terms. MPP.Methods.Tempo.Subscription.activate/4 deduplicates activations by challenge id, so presenting the captured credential under a fresh challenge produces a different dedup key, claim_activation succeeds, and the subscription transaction is built and broadcast again. Each replay charges the payer's wallet a new first-period settlement and re-authorizes the server key, bounded only by the subscription expiry and the chain's own semantics for re-installing an existing key. This issue affects mpp: from 0.14.0 before 0.16.2.

Read the publisher's advisory

Affected versions, risk and source history

cve-program · CVE-2026-87119

Published

mpp

https://repo.hex.pm

Publisher's version information

Shown as published. These rules are not interpreted as NuGet package version ranges.

{
                    "collectionURL": "https://repo.hex.pm",
                    "cpes": [
                        "cpe:2.3:a:ZenHive:mpp:*:*:*:*:*:*:*:*"
                    ],
                    "defaultStatus": "unaffected",
                    "modules": [
                        "'Elixir.MPP.Methods.Tempo.KeyAuthorization'",
                        "'Elixir.MPP.Methods.Tempo.Subscription'"
                    ],
                    "packageName": "mpp",
                    "packageURL": "pkg:hex/mpp",
                    "product": "mpp",
                    "programFiles": [
                        "lib/mpp/methods/tempo/key_authorization.ex",
                        "lib/mpp/methods/tempo/subscription.ex"
                    ],
                    "programRoutines": [
                        {
                            "name": "'Elixir.MPP.Methods.Tempo.KeyAuthorization':verify/3"
                        },
                        {
                            "name": "'Elixir.MPP.Methods.Tempo.KeyAuthorization':wallet_params/2"
                        },
                        {
                            "name": "'Elixir.MPP.Methods.Tempo.KeyAuthorization':from_rpc/1"
                        },
                        {
                            "name": "'Elixir.MPP.Methods.Tempo.Subscription':verify/2"
                        }
                    ],
                    "repo": "https://github.com/ZenHive/mpp",
                    "vendor": "ZenHive",
                    "versions": [
                        {
                            "lessThan": "0.16.2",
                            "status": "affected",
                            "version": "0.14.0",
                            "versionType": "semver"
                        }
                    ]
                }

zenhive/mpp

https://github.com

Publisher's version information

Shown as published. These rules are not interpreted as NuGet package version ranges.

{
                    "collectionURL": "https://github.com",
                    "cpes": [
                        "cpe:2.3:a:ZenHive:mpp:*:*:*:*:*:*:*:*"
                    ],
                    "defaultStatus": "unaffected",
                    "modules": [
                        "'Elixir.MPP.Methods.Tempo.KeyAuthorization'",
                        "'Elixir.MPP.Methods.Tempo.Subscription'"
                    ],
                    "packageName": "zenhive/mpp",
                    "packageURL": "pkg:github/zenhive/mpp",
                    "product": "mpp",
                    "programFiles": [
                        "lib/mpp/methods/tempo/key_authorization.ex",
                        "lib/mpp/methods/tempo/subscription.ex"
                    ],
                    "programRoutines": [
                        {
                            "name": "'Elixir.MPP.Methods.Tempo.KeyAuthorization':verify/3"
                        },
                        {
                            "name": "'Elixir.MPP.Methods.Tempo.KeyAuthorization':wallet_params/2"
                        },
                        {
                            "name": "'Elixir.MPP.Methods.Tempo.KeyAuthorization':from_rpc/1"
                        },
                        {
                            "name": "'Elixir.MPP.Methods.Tempo.Subscription':verify/2"
                        }
                    ],
                    "repo": "https://github.com/ZenHive/mpp",
                    "vendor": "ZenHive",
                    "versions": [
                        {
                            "lessThan": "4b6eaec02af0e8485cfb4ff68f467d075ed5dd6f",
                            "status": "affected",
                            "version": "db464dfa9a86ccda58f0827101f6da6bd8aafa78",
                            "versionType": "git"
                        }
                    ]
                }

Original source record · Cite this exact observation · Complete original publisher JSON