CVE-2026-34209
March 30, 2026
Impact 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. Patches Fixed in 0.4.11. Workarounds There are no workarounds available for this vulnerability.
Affected Packages
https://github.com/wevm/mppx.git (GITHUB):
Affected version(s) >=mppx@0.1.0 <mppx@0.4.11Fix Suggestion:
Update to version mppx@0.4.11https://github.com/wevm/mppx.git (GITHUB):
Affected version(s) >=mppx@0.1.0 <mppx@0.4.11Fix Suggestion:
Update to version mppx@0.4.11mppx (NPM):
Affected version(s) >=0.0.1 <0.4.11Fix Suggestion:
Update to version 0.4.11Related Resources (4)
Do you need more information?
Contact UsCVSS v4
Base Score:
8.7
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
NONE
Vulnerable System Confidentiality
NONE
Vulnerable System Integrity
HIGH
Vulnerable System Availability
NONE
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
7.5
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
HIGH
Availability
NONE
Weakness Type (CWE)
Authentication Bypass by Capture-replay
