Auth bypass in Multiversx Labs S.r.l. Multisig-Improved

CVE-2026-106511

MultiversX's multisig-improved (repository: mx-multisig-and-modules) reference implementation of their on-chain multisig smart contract system contains a vulnerability where a missing independent authorization check allows any account with the Proposer role to perform explicitly barred actions. This vulnerability allows the Proposer role to move funds alone, draining 100% of a contract's EGLD/ESDT balance in two transactions with zero signatures.

Vulnerability class: Broken Authentication

Published · last modified .

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-106511?
CVE-2026-106511 is a critical-severity vulnerability in Multiversx Labs S.r.l. Multisig-Improved, classified under Missing Authentication for Critical Function. CVSS score: 9.8/10. Published 2026-10-06.
How severe is CVE-2026-106511?
Critical severity. CVSS v3 base score is 9.8 out of 10.