CVE-2026-63628

mppx 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.

CVSS

No CVSS.

References

Link	Resource
https://github.com/wevm/mppx/commit/24ddcca719ae282977d8747309ed1275ea282b25
https://github.com/wevm/mppx/pull/602
https://github.com/wevm/mppx/releases/tag/mppx@0.8.2
https://github.com/wevm/mppx/security/advisories/GHSA-vc9j-9wph-qghj
https://github.com/wevm/mppx/security/advisories/GHSA-vc9j-9wph-qghj

Configurations

No configuration.

History

24 Sep 2026, 15:17

Type	Values Removed	Values Added
References	~~() https://github.com/wevm/mppx/security/advisories/GHSA-vc9j-9wph-qghj -~~	() https://github.com/wevm/mppx/security/advisories/GHSA-vc9j-9wph-qghj -

22 Sep 2026, 20:17

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-09-22 20:17

Updated : 2026-09-24 15:17

NVD link : CVE-2026-63628

Mitre link : CVE-2026-63628

CVE.ORG link : CVE-2026-63628

JSON object : View

Products Affected

No product.

CWE

CWE-20

Improper Input Validation

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