---
id: CVE-2026-31309
title: >-
  Improper authorization in the /tequilapi/config/user endpoint of Mysterium
  Node from v1.21.1-rc0 before v1.36.0 allows an unauthenticated attacker to
  arbitrarily overwrite the node's configuration and achieve a full node
  takeover via a c…
summary: >-
  Improper authorization in the /tequilapi/config/user endpoint of Mysterium
  Node from v1.21.1-rc0 before v1.36.0 allows an unauthenticated attacker to
  arbitrarily overwrite the node's configuration and achieve a full node
  takeover via a c…
severity: critical
cvss: 9.8
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'
cwe:
  - CWE-862
published: '2026-07-08'
updated: '2026-07-16'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-31309'
references:
  - url: 'https://github.com/mysteriumnetwork/node/'
    label: cve@mitre.org
  - url: >-
      https://github.com/mysteriumnetwork/node/commit/bc099fcaff59fee9c8a8f8e07ffff5b3c5df2bb9
    label: cve@mitre.org
  - url: 'https://github.com/sch8ill/CVE-2026-31309'
    label: cve@mitre.org
  - url: 'https://github.com/sch8ill/CVE-2026-31309'
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
tags:
  - nvd
  - exploit-available
epss: 0.0062
epssPercentile: 0.47494
ingestedAt: '2026-07-17T13:12:07.610Z'
exploits:
  github: 1
  githubRepos:
    - 'https://github.com/Sch8ill/CVE-2026-31309'
  checkedAt: '2026-09-26T09:05:41.735Z'
exploitAvailable: true
---

## Overview

Improper authorization in the /tequilapi/config/user endpoint of Mysterium Node from v1.21.1-rc0 before v1.36.0 allows an unauthenticated attacker to arbitrarily overwrite the node's configuration and achieve a full node takeover via a crafted POST request.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.