Vulnerability Description
Authentication Bypass by Capture-replay in ZenHive mpp allows an unauthenticated remote client to obtain paid resources by resubmitting one settled on-chain transfer. MPP.Methods.EVM.verify/2 accepts a transaction-hash credential and matches a transfer purely on token, to and amount (ERC-20) or to and value (native). It binds the proof neither to the challenge being verified nor to any record of prior use, and the generic MPP.Plug dedup store keys on challenge.id, which is regenerated for every 402 response. On a static-price route, a single historical transfer matching the charge therefore satisfies an unbounded number of later charges, including transfers an attacker can read off a public block explorer. This issue affects mpp: from 0.3.0 before 0.6.3.
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Zenhive | Machine Payments Protocol | >= 0.3.0, < 0.6.4 |
Related Weaknesses (CWE)
References
- https://cna.erlef.org/cves/CVE-2026-67581.htmlThird Party Advisory
- https://github.com/ZenHive/mpp/commit/ecc038088b1cda09ad8a84acc6cc112addb4a68fPatch
- https://github.com/ZenHive/mpp/security/advisories/GHSA-vp5h-xh25-44wfVendor Advisory
- https://osv.dev/vulnerability/EEF-CVE-2026-67581Third Party Advisory
FAQ
What is CVE-2026-67581?
CVE-2026-67581 is a vulnerability with a CVSS score of 7.5 (HIGH). Authentication Bypass by Capture-replay in ZenHive mpp allows an unauthenticated remote client to obtain paid resources by resubmitting one settled on-chain transfer. MPP.Methods.EVM.verify/2 accepts...
How severe is CVE-2026-67581?
CVE-2026-67581 has been rated HIGH with a CVSS base score of 7.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-67581?
Check the references section above for vendor advisories and patch information. Affected products include: Zenhive Machine Payments Protocol.