mppx: Tempo has a session close voucher bypass vulnerability due to settled amount equality
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 software
Click a technology to see all vulnerabilities affecting it.
| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| npm package | mppx | < 0.4.11 | 0.4.11 |
References
- CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N- Weakness (CWE)
CWE-294- Platform
- npm
- Package
mppx- Disclosed
- 29.03.2026
- Updated
- 11.10.2026 10:22
Sources and licenses
OSV / GitHub Advisory Database - GHSA-mv9j-8jvg-j8mr - CC BY 4.0
Vulnerability history: mppx
All published vulnerabilities of this package (npm package), newest first. Shows whether this is a one-off slip or a package that needs watching.
- Total entries
- 5
- First → latest
- 03.2026 09.2026
- Without a fix
- 0
- Exploited in attacks
- 0
Severity breakdown
- Critical 1
- High 1
- Medium 3
Disclosures per year
- 2026: 5
-
mppx: Tempo has a session close voucher bypass vulnerability due to settled amount equality this entry
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