CVE-2026-34209
HIGH
NVD
CVSS Score
7.5
Severity
HIGH
Published
Mar 31, 2026
Vendor
unknown
Description
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.