CVE-2026-73829Low· 3.7▾ SunlitTime-of-check Time-of-use (TOCTOU) Race Condition in ZenHive mpp allows an unauthenticated remote client to redeem one confirmed on-chain payment for multiple paid-resource accesses. The type="hash" credential path in MPP.Methods.Tempo.…
▾ Sunlit zone — Low / medium · no exploitation signal
impact 20.4 · likelihood 0 · exploitation 0
Need a working PoC? Pro members can cast a request and our team develops one — it lands right here.
Exploit-prediction probability, daily snapshots since Sep 10.
Disclosure to exploitation, from the record and what we observed since indexing it.
Disclosed via NVD
Last analysed / modified upstream
0.2%
Time-of-check Time-of-use (TOCTOU) Race Condition in ZenHive mpp allows an unauthenticated remote client to redeem one confirmed on-chain payment for multiple paid-resource accesses.
The type="hash" credential path in MPP.Methods.Tempo.verify/2 guards against replay with a non-atomic check-then-mark sequence: check_hash_unused/2 reads the dedup store, an eth_getTransactionReceipt round trip verifies the payment on chain, and only then does mark_hash_used/2 write the mark. Concurrent requests carrying the same settled payment hash all pass the read before any of them writes, so each is issued a receipt. The store's atomic check_and_mark/2 primitive is available and used by the type="transaction" path, but the hash path calls plain get and put even when the configured store implements it. Exploitation requires a dedup store to be configured; the default nil store is stateless and documented as offering no replay protection at all.
This issue affects mpp: from 0.2.0 before 0.6.1.
machine_payments_protocol >= 0.2.0, < 0.6.1Upgrade past the affected range:
machine_payments_protocol 0.6.1Connected by shared product, vendor, weakness, or advisory.
CVE-2026-23950High· 8.8node-tar,a Tar for Node.js, has a race condition vulnerability in versions up to and including 7.5.3
CVE-2026-67581High· 7.5Authentication Bypass by Capture-replay in ZenHive mpp allows an unauthenticated remote client to obtain paid resources by resubmitting one settled on-chain transfer. MPP.Methods.EVM.verify/2 accepts a transaction-hash credential and ma…
CVE-2026-73136High· 7.5Authentication 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 TransferWithM…
CVE-2026-73541High· 8.2Allocation of Resources Without Limits or Throttling in ZenHive mpp allows an unauthenticated remote client to drain the fee-payer wallet through concurrent sponsored payments, denying service to legitimate payers once it is empty. MPP.…
CVE-2026-29518High· 7.0Rsync versions before 3.4.3 contain a time-of-check to time-of-use (TOCTOU) race condition in daemon file handling that allows attackers to redirect file writes outside intended directories by replacing parent directory components with s…
CVE-2022-21198High· 7.9Time-of-check time-of-use race condition in the BIOS firmware for some Intel(R) Processors may allow a privileged user to potentially enable escalation of privilege via local access.