CVE Intelligence
High

CVE-2026-82750 — Unbounded EIP-7702 authorization list in mpp Tempo fee-payer sponsorship inflates gas cost and sponsors account delegation

Improper Validation of Specified Quantity in Input in ZenHive mpp allows an unauthenticated remote client to inflate the fee-payer's gas cost per sponsored payment by a large multiplier and to have the sponsor pay for EIP-7702 account delegations of the client's choosing. When the server sponsors Tempo payments, MPP.Methods.Tempo.FeePayerPolicy.measure/3 in lib/mpp/methods/tempo/fee_payer_policy.ex bounds the gas fields, the fee budget, the validity window and the access list of the client-signed 0x76 envelope, but never reads its aa_authorization_list field. Every signed delegation in that list is charged as intrinsic gas before the payment call runs, so a client attaching delegations from throwaway authority keys makes the sponsor pay for them within the default gas_limit ceiling. At the reporter's default of seven entries the sponsored cost rises from about 46,575 gas to about 1,884,087 gas. Because each entry is applied as a persistent set-code delegation, a client can also upgrade its own accounts to delegated code at the sponsor's expense. This issue affects mpp: from 0.2.0 before 0.16.1.

Published Sep 6, 2026 · Updated Oct 15, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · CNA: EEF

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.
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.

Exploitation
Not confirmed
Not in CISA KEV — an absence of record, not proof it is unexploited.
EPSS FIRST
—
No EPSS score.
Affects
Zenhive
Mpp
CVSS base
8.3
High · 2 source(s)

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.

Exploitation
None
none · proof-of-concept · active
Automatable
No
can an attacker script the kill-chain steps
Technical impact
Partial
partial · total control of the vulnerable component

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.

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.

  1. Identify exposed assets running the affected vendor/product/version combinations (Zenhive Mpp).
  2. The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
  3. No fix documented in the sources: reduce exposure and monitor the vendor advisory.
  4. Search available logs for exploit probes, errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

VendorProductVersionsStatusSource
Zenhive Mpp ≥ 0.2.0 and < 0.16.1≥ d29d54e507918db00a5b65d90136b73166c017d7 and < 0482572b47e1ffe1537ab80ab613d47b92833c2d Vulnerable CVE Program (cve.org) e CISA ADP

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector
Network
Attack complexity
Low
Attack requirements
Present
Privileges required
None
User interaction
None
Scope
X
Confidentiality (vulnerable system)
None
Integrity (vulnerable system)
High
Availability (vulnerable system)
Low
Confidentiality (subsequent)
None
Integrity (subsequent)
None
Availability (subsequent)
None

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

ScoreVersionSeverityExpl.ImpactScored 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
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X (score shown at the top: 6b3ad84c-e1a6-4bf7-a703-f496b71e49db)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-1284

Other CVEs with this weakness →

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).
web/proxy/WAF logsnetwork IDS/IPS

Timeline

What happened to this CVE, newest first.

  • 2026
  • Affected products added · zenhive/mpp
    Oct 15, 2026 · CVE Program (cve.org) e CISA ADP
  • SSVC assessment updated
    Oct 15, 2026 · CVE Program (cve.org) e CISA ADP
  • Record published
    Oct 15, 2026
  • CVSS changed · 8.3
    Oct 15, 2026 · NIST National Vulnerability Database
  • Source status changed · → Deferred
    Oct 15, 2026 · NIST National Vulnerability Database
  • Record created in this database
    Oct 15, 2026 · NIST National Vulnerability Database
  • CVE published
    Sep 6, 2026 · EEF

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

Zenhive
every CVE for this vendor
CWE-1284
other pages naming this weakness

Related CVEs (same products)

  • CVE-2026-82751 Unbounded key authorization in mpp Tempo fee-payer sponsorship inflates gas cost and sponsors access-key provisioning Sep 6, 2026
  • CVE-2026-73136 Static memo configuration in mpp Tempo disables per-challenge attribution binding, enabling third-party replay Aug 19, 2026
  • CVE-2026-73541 Tempo fee sponsorship in mpp bounds each transaction but not aggregate exposure, allowing concurrent sponsor-wallet drain Aug 19, 2026
  • CVE-2026-73829 Non-atomic hash-credential dedup in mpp Tempo allows replay of a confirmed payment under a concurrent race Aug 19, 2026
  • CVE-2026-67581 On-chain transfer proof is not single-use in mpp EVM payment method, enabling cross-challenge replay Aug 19, 2026
  • CVE-2026-59695 Unbounded max_fee_per_gas in mpp Tempo fee-payer enables single-request wallet drain 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 fixed version, patch or mitigation documented.
  • 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-2026-82750 is "Unbounded EIP-7702 authorization list in mpp Tempo fee-payer sponsorship inflates gas cost and sponsors account delegation", rated High. It affects Mpp (Zenhive); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 8.3 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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