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Fencer Vulns
critical 9.8

CVE-2026-31309 json

Improper authorization in the /tequilapi/config/user endpoint of Mysterium Node from v1.21.1-rc0 before v1.36.0 allows an unauthenticated a…

published 2026-07-08 4 mo ago modified 2026-07-16 3 mo ago also EUVD-2026-42495

cvss
9.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.6%
EPSS 0.6% chance of exploitation in 30 days, percentile 49%
public exploits
0
none known

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 crafted POST request.

Patch / fix

CISA SSVC

Exploitation
Proof of concept is public
Automatable
yes
Technical impact
total
Assessed
3 mo ago

Exploit prediction

0.62% chance of exploitation in the next 30 days, higher than 49% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/sch8ill/CVE-2026-31309 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CISA ADP 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CNA 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.