CVE-2026-73541 — Tempo fee sponsorship in mpp bounds each transaction but not aggregate exposure, allowing concurrent sponsor-wallet drain
Allocation 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.Methods.Tempo.FeePayerPolicy enforces its ceilings (max_gas, max_fee_per_gas, max_priority_fee_per_gas, the worst-case gas_limit * max_fee_per_gas <= max_total_fee budget cap, and a validity window) against one transaction at a time, and nothing accounts for exposure across concurrent requests. reserve_hash_atomic/2 is keyed on the transaction hash, so it prevents duplicate broadcast of the same signed transaction but not N distinct sponsored transactions carrying distinct expiring nonces. Committed sponsor exposure is therefore N times max_total_fee, bounded by nothing in the library, and the default 900 second validity window lets co-signed transactions stay broadcastable and uncounted for that entire period. This issue affects mpp: from 0.2.0 before 0.12.0.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- Technical severity (high)+6
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
CISA SSVC assessment CISA
Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
- Documented mitigation — cna.erlef.org (NIST National Vulnerability Database)
- Documented patch — github.com (NIST National Vulnerability Database)
- Documented mitigation — osv.dev (NIST National Vulnerability Database)
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Zenhive Machine Payments Protocol, Zenhive Mpp).
- The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
- Apply the fixed version or the patch documented under Remediation.
- Search available logs for exploit probes matching the vulnerability class (denial of service), errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Zenhive | Machine Payments Protocol | ≥ 0.2.0 and < 0.12.0 | Vulnerable | NIST National Vulnerability Database |
| Zenhive | Mpp | ≥ 0.2.0 and < 0.12.0≥ d29d54e507918db00a5b65d90136b73166c017d7 and < ddc46868fba57ccebb567c04709812b466123076 | Vulnerable | CVE Program (cve.org) e CISA ADP |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 8.3 | CVSS 4.0 | High | — | — | 6b3ad84c-e1a6-4bf7-a703-f496b71e49db via NIST National Vulnerability Database |
| 8.3 | CVSS 4.0 | High | — | — | EEF via CVE Program (cve.org) e CISA ADP |
| 8.2 | CVSS 3.1 | High | 3.9 | 4.2 | nvd@nist.gov via NIST National Vulnerability Database |
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H (score shown at the top: nvd@nist.gov) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
CWE-770 · Allocation of Resources Without Limits or Throttling
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
- Track CPU/memory spikes and availability drops correlated with request patterns.
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · zenhive/mpp
- SSVC assessment updated
- Record published
- Fix documented
- CVSS changed · 8.2
- Source status changed · → Analyzed
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× Official description updated · Oct 15, 2026 – Oct 15, 2026
References
4 on the record
Elsewhere on this site
Related CVEs (same products)
- High CVE-2026-73136 Static memo configuration in mpp Tempo disables per-challenge attribution binding, enabling third-party replay Aug 19, 2026
- Low CVE-2026-73829 Non-atomic hash-credential dedup in mpp Tempo allows replay of a confirmed payment under a concurrent race Aug 19, 2026
- High CVE-2026-67581 On-chain transfer proof is not single-use in mpp EVM payment method, enabling cross-challenge replay Aug 19, 2026
- High CVE-2026-59695 Unbounded max_fee_per_gas in mpp Tempo fee-payer enables single-request wallet drain Jul 17, 2026
- High CVE-2026-59252 Missing gas_limit validation in mpp Tempo fee-payer enables wallet drain Jul 17, 2026
- High CVE-2026-59694 Unbounded access list in mpp Tempo fee-payer inflates gas cost per payment Jul 17, 2026
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No FIRST EPSS score.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2026-73541 is "Tempo fee sponsorship in mpp bounds each transaction but not aggregate exposure, allowing concurrent sponsor-wallet drain", rated High. It affects Machine Payments Protocol (Zenhive); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 8.2 describes technical severity. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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