Vulnerability-Lookup

GHSA-H97R-55W6-6RFG

Vulnerability from github – Published: 2026-09-22 12:30 – Updated: 2026-09-22 12:30

Details

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.

Severity

8.2 (High)


                  
                    CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N

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{
  "affected": [],
  "aliases": [
    "CVE-2026-87119"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-294"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-09-22T12:17:14Z",
    "severity": "HIGH"
  },
  "details": "Authentication Bypass by Capture-replay in ZenHive mpp allows an attacker holding a captured subscription activation credential to charge the payer repeatedly.\n\nThe 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\u0027s wallet a new first-period settlement and re-authorizes the server key, bounded only by the subscription expiry and the chain\u0027s own semantics for re-installing an existing key.\n\nThis issue affects mpp: from 0.14.0 before 0.16.2.",
  "id": "GHSA-h97r-55w6-6rfg",
  "modified": "2026-09-22T12:30:26Z",
  "published": "2026-09-22T12:30:26Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/ZenHive/mpp/security/advisories/GHSA-p9fv-9w58-95x2"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-87119"
    },
    {
      "type": "WEB",
      "url": "https://github.com/ZenHive/mpp/commit/4b6eaec02af0e8485cfb4ff68f467d075ed5dd6f"
    },
    {
      "type": "WEB",
      "url": "https://github.com/ZenHive/mpp/commit/db464dfa9a86ccda58f0827101f6da6bd8aafa78"
    },
    {
      "type": "WEB",
      "url": "https://cna.erlef.org/cves/CVE-2026-87119.html"
    },
    {
      "type": "WEB",
      "url": "https://osv.dev/vulnerability/EEF-CVE-2026-87119"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
      "type": "CVSS_V4"
    }
  ]
}

CVE-2026-87119 (GCVE-0-2026-87119)

Vulnerability from cvelistv5 – Published: 2026-09-22 11:16 – Updated: 2026-09-22 12:02

Title

mpp Tempo subscription key authorization is not bound to the issuing challenge, allowing a captured activation credential to be replayed

Summary

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.

Severity

8.2 (High)


                        
                          CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-09-22 12:02 UTC

CWE

CWE-294 - Authentication Bypass by Capture-replay

Assigner

EEF mitre root

References

5 references

URL	Tags
https://github.com/ZenHive/mpp/security/advisorie…	relatedvendor-advisory
https://cna.erlef.org/cves/CVE-2026-87119.html	related
https://osv.dev/vulnerability/EEF-CVE-2026-87119	related
https://github.com/ZenHive/mpp/commit/db464dfa9a8…	related
https://github.com/ZenHive/mpp/commit/4b6eaec02af…	patch

Impacted products

2 products

Vendor	Product	Version
ZenHive	mpp	Affected: 0.14.0 , < 0.16.2 (semver) cpe:2.3:a:ZenHive:mpp::::::::
ZenHive	mpp	Affected: db464dfa9a86ccda58f0827101f6da6bd8aafa78 , < 4b6eaec02af0e8485cfb4ff68f467d075ed5dd6f (git) cpe:2.3:a:ZenHive:mpp::::::::

Credits

E.FU E.FU Jonatan Männchen / EEF

Show details on NVD website

JSON

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{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-87119",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-09-22T12:02:12.184296Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-09-22T12:02:31.484Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
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          "collectionURL": "https://repo.hex.pm",
          "cpes": [
            "cpe:2.3:a:ZenHive:mpp:*:*:*:*:*:*:*:*"
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          "defaultStatus": "unaffected",
          "modules": [
            "\u0027Elixir.MPP.Methods.Tempo.KeyAuthorization\u0027",
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          "packageName": "mpp",
          "packageURL": "pkg:hex/mpp",
          "product": "mpp",
          "programFiles": [
            "lib/mpp/methods/tempo/key_authorization.ex",
            "lib/mpp/methods/tempo/subscription.ex"
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          "programRoutines": [
            {
              "name": "\u0027Elixir.MPP.Methods.Tempo.KeyAuthorization\u0027:verify/3"
            },
            {
              "name": "\u0027Elixir.MPP.Methods.Tempo.KeyAuthorization\u0027:wallet_params/2"
            },
            {
              "name": "\u0027Elixir.MPP.Methods.Tempo.KeyAuthorization\u0027:from_rpc/1"
            },
            {
              "name": "\u0027Elixir.MPP.Methods.Tempo.Subscription\u0027:verify/2"
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          "vendor": "ZenHive",
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          "cpes": [
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          "packageURL": "pkg:github/zenhive/mpp",
          "product": "mpp",
          "programFiles": [
            "lib/mpp/methods/tempo/key_authorization.ex",
            "lib/mpp/methods/tempo/subscription.ex"
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          "programRoutines": [
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            },
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          "versions": [
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              "version": "db464dfa9a86ccda58f0827101f6da6bd8aafa78",
              "versionType": "git"
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          ]
        }
      ],
      "configurations": [
        {
          "lang": "en",
          "supportingMedia": [
            {
              "base64": false,
              "type": "text/html",
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            },
            {
              "base64": false,
              "type": "text/markdown",
              "value": "Only deployments offering Tempo subscriptions are affected, which requires `subscription_access_key_private_key` in the Tempo `method_config`. Exploitation further requires the attacker to have obtained a payer\u0027s signed activation credential, in transit over a hop that is not TLS-protected or at rest in a log, an intermediary, or a client retry buffer."
            }
          ],
          "value": "Only deployments offering Tempo subscriptions are affected, which requires subscription_access_key_private_key in the Tempo method_config. Exploitation further requires the attacker to have obtained a payer\u0027s signed activation credential, in transit over a hop that is not TLS-protected or at rest in a log, an intermediary, or a client retry buffer."
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:a:ZenHive:mpp:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "0.16.2",
                  "versionStartIncluding": "0.14.0",
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          "type": "remediation developer",
          "value": "E.FU"
        },
        {
          "lang": "en",
          "type": "coordinator",
          "value": "Jonatan M\u00e4nnchen / EEF"
        }
      ],
      "dateAssigned": "2026-09-15T15:20:31.000Z",
      "descriptions": [
        {
          "lang": "en",
          "supportingMedia": [
            {
              "base64": false,
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              "value": "\u003cp\u003eAuthentication Bypass by Capture-replay in ZenHive mpp allows an attacker holding a captured subscription activation credential to charge the payer repeatedly.\u003c/p\u003e\n\u003cp\u003eThe payer signs a Tempo \u003ccode\u003eKeyAuthorization\u003c/code\u003e over the chain id, key type, key id, expiry, limits and scopes only, with nothing tying it to the challenge that prompted it. \u003ccode\u003eMPP.Methods.Tempo.KeyAuthorization.verify/3\u003c/code\u003e in \u003ccode\u003elib/mpp/methods/tempo/key_authorization.ex\u003c/code\u003e 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. \u003ccode\u003eMPP.Methods.Tempo.Subscription.activate/4\u003c/code\u003e deduplicates activations by challenge id, so presenting the captured credential under a fresh challenge produces a different dedup key, \u003ccode\u003eclaim_activation\u003c/code\u003e succeeds, and the subscription transaction is built and broadcast again. Each replay charges the payer\u0027s wallet a new first-period settlement and re-authorizes the server key, bounded only by the subscription expiry and the chain\u0027s own semantics for re-installing an existing key.\u003c/p\u003e\n\u003cp\u003eThis issue affects mpp: from 0.14.0 before 0.16.2.\u003c/p\u003e"
            },
            {
              "base64": false,
              "type": "text/markdown",
              "value": "Authentication Bypass by Capture-replay in ZenHive mpp allows an attacker holding a captured subscription activation credential to charge the payer repeatedly.\n\nThe 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\u0027s wallet a new first-period settlement and re-authorizes the server key, bounded only by the subscription expiry and the chain\u0027s own semantics for re-installing an existing key.\n\nThis issue affects mpp: from 0.14.0 before 0.16.2."
            }
          ],
          "value": "Authentication Bypass by Capture-replay in ZenHive mpp allows an attacker holding a captured subscription activation credential to charge the payer repeatedly.\n\nThe 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\u0027s wallet a new first-period settlement and re-authorizes the server key, bounded only by the subscription expiry and the chain\u0027s own semantics for re-installing an existing key.\n\nThis issue affects mpp: from 0.14.0 before 0.16.2."
        }
      ],
      "impacts": [
        {
          "capecId": "CAPEC-60",
          "descriptions": [
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              "lang": "en",
              "supportingMedia": [
                {
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                  "type": "text/html",
                  "value": "\u003cp\u003eAn attacker who obtains a payer\u0027s subscription activation credential (from a non-TLS hop, a log, a compromised intermediary, or the client\u0027s own retry buffer) can present it under fresh challenges to settle repeated first-period charges against that payer\u0027s wallet and re-authorize the server\u0027s access key. The payer bears the on-chain cost, limited only by the per-period subscription limit and the subscription expiry.\u003c/p\u003e"
                },
                {
                  "base64": false,
                  "type": "text/markdown",
                  "value": "An attacker who obtains a payer\u0027s subscription activation credential (from a non-TLS hop, a log, a compromised intermediary, or the client\u0027s own retry buffer) can present it under fresh challenges to settle repeated first-period charges against that payer\u0027s wallet and re-authorize the server\u0027s access key. The payer bears the on-chain cost, limited only by the per-period subscription limit and the subscription expiry."
                }
              ],
              "value": "An attacker who obtains a payer\u0027s subscription activation credential (from a non-TLS hop, a log, a compromised intermediary, or the client\u0027s own retry buffer) can present it under fresh challenges to settle repeated first-period charges against that payer\u0027s wallet and re-authorize the server\u0027s access key. The payer bears the on-chain cost, limited only by the per-period subscription limit and the subscription expiry."
            }
          ]
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "Automatable": "NOT_DEFINED",
            "Recovery": "NOT_DEFINED",
            "Safety": "NOT_DEFINED",
            "attackComplexity": "HIGH",
            "attackRequirements": "PRESENT",
            "attackVector": "NETWORK",
            "baseScore": 8.2,
            "baseSeverity": "HIGH",
            "privilegesRequired": "NONE",
            "providerUrgency": "NOT_DEFINED",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "NONE",
            "valueDensity": "NOT_DEFINED",
            "vectorString": "CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N",
            "version": "4.0",
            "vulnAvailabilityImpact": "NONE",
            "vulnConfidentialityImpact": "NONE",
            "vulnIntegrityImpact": "HIGH",
            "vulnerabilityResponseEffort": "NOT_DEFINED"
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          "format": "CVSS",
          "scenarios": [
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              "lang": "en",
              "value": "GENERAL"
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        {
          "descriptions": [
            {
              "cweId": "CWE-294",
              "description": "CWE-294 Authentication Bypass by Capture-replay",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-22T11:16:56.232Z",
        "orgId": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
        "shortName": "EEF"
      },
      "references": [
        {
          "name": "GitHub Advisory",
          "tags": [
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            "vendor-advisory"
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          "url": "https://github.com/ZenHive/mpp/security/advisories/GHSA-p9fv-9w58-95x2"
        },
        {
          "name": "EEF CNA record for CVE-2026-87119",
          "tags": [
            "related"
          ],
          "url": "https://cna.erlef.org/cves/CVE-2026-87119.html"
        },
        {
          "name": "OSV record EEF-CVE-2026-87119",
          "tags": [
            "related"
          ],
          "url": "https://osv.dev/vulnerability/EEF-CVE-2026-87119"
        },
        {
          "name": "Introducing commit db464df in ZenHive/mpp",
          "tags": [
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        {
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        }
      ],
      "source": {
        "discovery": "INTERNAL"
      },
      "title": "mpp Tempo subscription key authorization is not bound to the issuing challenge, allowing a captured activation credential to be replayed"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
    "assignerShortName": "EEF",
    "cveId": "CVE-2026-87119",
    "datePublished": "2026-09-22T11:16:56.232Z",
    "dateReserved": "2026-09-11T18:00:02.032Z",
    "dateUpdated": "2026-09-22T12:02:31.484Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

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GHSA-H97R-55W6-6RFG

CVE-2026-87119 (GCVE-0-2026-87119)

Tags

Sightings

Nomenclature

Related by attack behaviour