PT-2026-28607 · Npm · Mppx

Published 2026-03-29 · Updated 2026-03-29 · CVE-2026-34209

OSV

CVSS v3.1

7.5

High

AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

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.

Fix

Weakness Enumeration

CWE-294

Related Identifiers

CVE-2026-34209

GHSA-MV9J-8JVG-J8MR

Affected Products

Mppx

References · 5

• https://osv.dev/vulnerability/GHSA-mv9j-8jvg-j8mr · Vendor Advisory
• https://github.com/wevm/mppx/releases/tag/mppx@0.4.11 · Note
• https://github.com/wevm/mppx/commit/94088246ee18f21b5d6be40d9e7a464f5a280bfb · Note
• https://github.com/wevm/mppx · Note
• https://github.com/wevm/mppx/security/advisories/GHSA-mv9j-8jvg-j8mr · Note