mppx: Gas Draining with access list

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-63628
StatePUBLISHED
AssignerGitHub_M
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-09-22 20:17:04 UTC
Updated2026-09-24 15:17:26 UTC
Descriptionmppx is a TypeScript interface for machine payments protocol. Prior to 0.8.2, the fee-payer cosigning path in src/tempo/internal/fee-payer.ts copied a client-supplied access_list from a 0x78 FeePayerEnvelope without validating its length or contents. Because EIP-2930 access-list entries consume intrinsic gas even when the listed addresses are never used, a client could add fabricated address-only entries and cause the server fee_payer wallet to pay unnecessary transaction fees. The demonstrated 180-entry list remained within the 500,000 gas policy cap, 16 KB header limit, and RPC simulation budget while increasing the fee by approximately 9.4 times. This issue is fixed in version 0.8.2.

Risk And Classification

Primary CVSS: v4.0 6.9 MEDIUM from [email protected]

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/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

EPSS: 0.003840000 probability, percentile 0.295920000 (date 2026-09-24)

Problem Types: CWE-20 | CWE-20 CWE-20: Improper Input Validation

VersionSourceTypeScoreSeverityVector
4.0[email protected]Secondary6.9MEDIUMCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/C...
4.0CNADECLARED6.9MEDIUMCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N

CVSS v4.0 Breakdown

Attack Vector
Network
Attack Complexity
Low
Attack Requirements
None
Privileges Required
None
User Interaction
None
Confidentiality
None
Integrity
None
Availability
Low
Sub Conf.
None
Sub Integrity
None
Sub Availability
None

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/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

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Wevm Mppx affected < 0.8.2 Not specified

References

ReferenceSourceLinkTags
github.com/wevm/mppx/releases/tag/[email protected] [email protected] github.com
github.com/wevm/mppx/commit/24ddcca719ae282977d8747309ed1275ea282b25 [email protected] github.com
github.com/wevm/mppx/pull/602 [email protected] github.com
github.com/wevm/mppx/security/advisories/GHSA-vc9j-9wph-qghj 134c704f-9b21-4f2e-91b3-4a467353bcc0 github.com
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