Auth bypass in N/a

CVE-2026-31309

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.

Vulnerability class: Broken Access Control

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

EPSS: 0.006 (48.1th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 48th percentile — 48.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-31309: held from 0.006 to 0.006.

EPSS over last 30 days · oldest: 0.006 · newest: 0.006 · change: 0.000

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2026-31309?
CVE-2026-31309 is a critical-severity vulnerability in N/a, classified under Missing Authorization. CVSS score: 9.8/10. Published 2026-07-08.
How severe is CVE-2026-31309?
Critical severity. CVSS v3 base score is 9.8 out of 10.
Is CVE-2026-31309 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.