MPP.Methods.Tempo normally binds a settled TIP-20 TransferWithMemo to the specific challenge under verification through an attribution nonce carried in the memo. When a static "memo" is configured in method_config, check_matched_memo_binding/3 returns the match unconditionally and that binding is skipped, leaving only token, recipient, amount and the static memo value to match on. The static memo is echoed in every unauthenticated 402 response and Tempo transfers are public, so an attacker can take any matching transfer paid by a legitimate customer, request a fresh challenge for the same route, and present that transaction hash as a type="hash" credential. The hash path performs no sender or signature check tying the presenter to the wallet that broadcast the transfer.
This issue affects mpp: from 0.6.1 before 0.6.4.
Analysis and contextual insights are available on OpenCVE Cloud.
Vendor Workaround
Remove the static "memo" from the Tempo method_config so verification falls back to the default per-challenge attribution binding, which ties each settled transfer to the challenge being verified. Where a static memo must be kept, configure a dedup store (for example MPP.Tempo.ConCacheStore) with a TTL at least as long as the challenge expiry, which reduces unlimited replay to a race on the transaction hash rather than closing it.
Tracking
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Wed, 19 Aug 2026 19:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Metrics |
ssvc
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Wed, 19 Aug 2026 19:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Zenhive
Zenhive mpp |
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| Vendors & Products |
Zenhive
Zenhive mpp |
Wed, 19 Aug 2026 17:30:00 +0000
| Type | Values Removed | Values Added |
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| Description | Authentication Bypass by Capture-replay in ZenHive mpp allows an unauthenticated third party to obtain paid resources by replaying a transfer settled by an unrelated payer. MPP.Methods.Tempo normally binds a settled TIP-20 TransferWithMemo to the specific challenge under verification through an attribution nonce carried in the memo. When a static "memo" is configured in method_config, check_matched_memo_binding/3 returns the match unconditionally and that binding is skipped, leaving only token, recipient, amount and the static memo value to match on. The static memo is echoed in every unauthenticated 402 response and Tempo transfers are public, so an attacker can take any matching transfer paid by a legitimate customer, request a fresh challenge for the same route, and present that transaction hash as a type="hash" credential. The hash path performs no sender or signature check tying the presenter to the wallet that broadcast the transfer. This issue affects mpp: from 0.6.1 before 0.6.4. | |
| Title | Static memo configuration in mpp Tempo disables per-challenge attribution binding, enabling third-party replay | |
| First Time appeared |
Zenhive
Zenhive mpp |
|
| Weaknesses | CWE-294 | |
| CPEs | cpe:2.3:a:ZenHive:mpp:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Zenhive
Zenhive mpp |
|
| References |
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| Metrics |
cvssV4_0
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Status: PUBLISHED
Assigner: EEF
Published:
Updated: 2026-08-19T18:54:00.153Z
Reserved: 2026-08-18T10:00:02.159Z
Link: CVE-2026-73136
Updated: 2026-08-19T18:53:16.731Z
Status : Received
Published: 2026-08-19T18:17:25.453
Modified: 2026-08-19T19:17:24.140
Link: CVE-2026-73136
No data.
OpenCVE Enrichment
Updated: 2026-08-19T19:00:04Z