CVE-2026-73829Network attack vector

Payment replay via non-atomic hash dedup

Published Aug 19, 2026 · Updated Aug 19, 2026

Race condition in ZenHive MPP before 0.6.1 allows remote attackers to redeem one confirmed on-chain payment for multiple paid-resource accesses via hash credentials. In MPP.Methods.Tempo.verify/2, the type="hash" path reads the dedup store with check_hash_unused/2, fetches the on-chain receipt, and only then records the hash as used, so concurrent requests can all pass the read before any request commits the mark. Reachability requires a configured dedup store, and the consequence is repeated access to paid resources rather than code execution or broader system compromise.

CVSS severity6.3
Medium
EPSS probability0.19%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Race condition in ZenHive MPP before 0.6.1 allows remote attackers to redeem one confirmed on-chain payment for multiple paid-resource accesses via hash credentials. In MPP.Methods.Tempo.verify/2, the type="hash" path reads the dedup store with check_hash_unused/2, fetches the on-chain receipt, and only then records the hash as used, so concurrent requests can all pass the read before any request commits the mark. Reachability requires a configured dedup store, and the consequence is repeated access to paid resources rather than code execution or broader system compromise.

The record

CVE
CVE-2026-73829
Published
Aug 19, 2026
Updated
Aug 19, 2026
Vendor
ZenHive
Product
MPP
Classifications
CWE-367, CAPEC-29
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 19, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 19, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0.2.0 <0.6.1
  2. Affected versionversion=f8904666061fbab695874856d8fcd02c471dfe1b <46c5b0e1311da7d92190dc7d9ea89027a1d365e9

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

ZenHive · MPPversion=0.2.0 <0.6.1; version=f8904666061fbab695874856d8fcd02c471dfe1b <46c5b0e1311da7d92190dc7d9ea89027a1d365e9

Published CVSS scores

6.3ERLEF CNACVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-367Time-of-check Time-of-use (TOCTOU) Race Condition
CAPEC-29Leveraging Time-of-Check and Time-of-Use (TOCTOU) Race Conditions

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo