CVE-2026-34209
mppx: Tempo has a session close voucher bypass vulnerability due to settled amount equality
CVSS Score
7.5
EPSS Score
0.0%
EPSS Percentile
7th
mppx is a TypeScript interface for machine payments protocol. Prior to version 0.4.11, the tempo/session cooperative close handler validated the close voucher amount using "<" instead of "<=" against the on-chain settled amount. An attacker could submit a close voucher exactly equal to the settled amount, which would be accepted without committing any new funds, effectively closing or griefing the channel for free. This issue has been patched in version 0.4.11.
| CWE | CWE-294 |
| Vendor | wevm |
| Product | mppx |
| Published | Mar 31, 2026 |
| Last Updated | Apr 2, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
High
Availability
None
Affected Versions
wevm / mppx
< 0.4.11