Missing gas_limit validation in mpp Tempo fee-payer enables wallet drain
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Attack requirements
- Present
- Impact type
- —
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Fixed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA.
Summary
Improper Validation of Specified Quantity in Input in ZenHive mpp allows an unauthenticated remote client to drain the fee-payer wallet, resulting in denial of service for legitimate clients. When the mpp Elixir library is configured as fee payer (fee_payer: true), the MPP.Methods.Tempo payment method co-signs and broadcasts a client-supplied EVM transaction without first validating that the client-supplied gas_limit is sufficient to complete the intended call. A malicious client can submit a signed transferWithMemo transaction with gas_limit deliberately set just below the amount required for successful execution. The server co-signs the transaction and broadcasts it via rpc_broadcast_sync. The transaction runs out of gas during EVM execution and reverts, but the fee-payer wallet is still charged for the burned gas while the client pays nothing and receives no resource. Repeated requests from one or more malicious clients drain the fee-payer wallet at near-zero cost to the attacker, ultimately preventing the server from sponsoring gas for legitimate payment requests. The wait_for_confirmation = false (optimistic) path is also affected: it invokes simulate_payment_call via eth_call, but that simulation omits the gas parameter and therefore does not catch out-of-gas conditions. This issue affects mpp: from 0.2.0 before 0.6.0.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| ZenHive | mpp | 0.2.0 to before 0.6.0 | 0.6.0 | Patch available | CNA |
- mpp VendorZenHive Affected 0.2.0 to before 0.6.0 Fixed in 0.6.0 Patch available CNA
CPE names CNA · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:ZenHive:mpp:*:*:*:*:*:*:*:* | — | — | — |
- cpe:2.3:a:ZenHive:mpp:*:*:*:*:*:*:*:* Versions — — ·—
Remediation
- Fix · CNA mpp (ZenHive) Fixed in 0.6.0
Fixed in the same release
Records fixed by the same vendor advisory or release, as the CNA lists them.
- Release ·
ZenHive mpp 0.6.0
3 records Highest priority Priority HIGH 3 HIGH
Other records, highest priority first
- TI-2026-42571 Unbounded max_fee_per_gas in mpp Tempo fee-payer enables single-request wallet drainPriority HIGH 71
- TI-2026-42570 Unbounded access list in mpp Tempo fee-payer inflates gas cost per paymentPriority HIGH 69
Timeline
- 2026-10-02 Threatist record created from CVE-2026-59252
- 2026-10-03 Alias added: GHSA-vp7w-82cm-hj3h
References
More ZenHive vulnerabilities
- TI-2026-42571 Unbounded max_fee_per_gas in mpp Tempo fee-payer enables single-request wallet drain CVSS 4.0HIGH 8.3
- TI-2026-42570 Unbounded access list in mpp Tempo fee-payer inflates gas cost per payment CVSS 4.0HIGH 8.3
- TI-2026-60473 Session voucher adding no new funds is accepted without a charge in mpp, serving paid resources for free CVSS 4.0HIGH 7.1
- TI-2026-47746 On-chain transfer proof is not single-use in mpp EVM payment method, enabling cross-challenge replay CVSS 4.0HIGH 8.7
- TI-2026-51635 Resource allocation without limits in ZenHive mpp CVSS 4.0HIGH 8.3
- TI-2026-57069 Unbounded key authorization in mpp Tempo fee-payer sponsorship inflates gas cost and sponsors access-key provisioning CVSS 4.0HIGH 8.3
Sources
- CVE-2026-59252 · CVE Program
- CVE-2026-59252 · NVD
- FIRST EPSS
- GHSA-vp7w-82cm-hj3h · GitHub Advisory Database · CC BY 4.0
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