PT-2026-28607 · Mppx · Mppx

Samczsun + 1 · Published 2026-03-29 · Updated 2026-03-31 · CVE-2026-34209

Positive Technologies (AI Summary)

CVSS v3.1

7.5

High

Base vector

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

Name of the Vulnerable Software and Affected Versions mppx versions prior to 0.4.11

Description mppx is a TypeScript interface for machine payments protocol. The tempo/session cooperative close handler incorrectly validated the close voucher amount using '<' instead of '<=' against the on-chain settled amount. This allowed an attacker to submit a close voucher equal to the settled amount, bypassing fund commitment and potentially closing or disrupting the channel. The vulnerable component is the tempo/session cooperative close handler.

Recommendations Update to version 0.4.11 or later.

Exploit

Fix

Weakness Enumeration

CWE-294

Related Identifiers

CVE-2026-34209

GHSA-MV9J-8JVG-J8MR

Affected Products

Mppx

References · 9

• 🔥 https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/34xxx/CVE-2026-34209.json · Exploit
• https://github.com/wevm/mppx/security/advisories/GHSA-mv9j-8jvg-j8mr · Vendor Advisory
• https://github.com/wevm/mppx/commit/94088246ee18f21b5d6be40d9e7a464f5a280bfb · Patch
• https://nvd.nist.gov/vuln/detail/CVE-2026-34209 · Security Note
• https://osv.dev/vulnerability/GHSA-mv9j-8jvg-j8mr · Vendor Advisory
• https://osv.dev/vulnerability/CVE-2026-34209 · Vendor Advisory
• https://github.com/wevm/mppx · Note
• https://github.com/wevm/mppx/releases/tag/mppx@0.4.11 · Note
• https://twitter.com/CVEnew/status/2039004436324815038 · Twitter Post