Replay Attack Affecting mppx package, versions <0.4.11
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-JS-MPPX-15857147
- published31 Mar 2026
- disclosed29 Mar 2026
- creditsamczsun, Veria Labs
Introduced: 29 Mar 2026
CVE-2026-34209 (opens in a new tab)How to fix?
Upgrade mppx to version 0.4.11 or higher.
Overview
mppx is a 
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Affected versions of this package are vulnerable to Replay Attack in the tempo/session cooperative close handler due to improper validation of the close voucher amount. An attacker can bypass intended restrictions by submitting a close voucher with an amount exactly equal to the on-chain settled amount, allowing them to close or disrupt the channel without committing new funds.