MrSteam iSteamX Improper Isolation or Compartmentalization

published 2026-09-24 45 d ago modified 2026-09-25 44 d ago also EUVD-2026-86468

cvss: 9.6; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.3%; EPSS 0.3% chance of exploitation in 30 days, percentile 22%
public exploits: 0; none known

Prior to 9/18/2026, the iSteamX mobile application's AWS policy could grant authenticated users access to wildcard MQTT topics, which can expose other users' device data and allow the attacker to start and stop other connected users' devices. This risked exposing user profile information and potential scalding due to unintended device activation.

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

cisa vex VA-26-267-01 updated 2026-09-24 cvss 9.6

MrSteam iSteamX

MrSteam iSteamX application v1.3.42_(build_44) MrSteam iSteamX Hub firmware v4.2.1
affected: vendor fix mrsteam.com

From CISA ICS and IT advisories (CSAF, https://github.com/cisagov/CSAF), a U.S. Government work; changed: reduced to products, statuses and remediations. CISA notification · csaf

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: partial
Assessed: 44 d ago (2026-09-25)

Exploit prediction

0.30% chance of exploitation in the next 30 days, higher than 22% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	4.0	8.4	CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:L/SI:N/SA:H
CNA	3.1	9.6	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:H
CNA	4.0	8.4	CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:L/SI:N/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Affected products

MrSteam iSteamX application
MrSteam iSteamX Hub

Classification

Weakness

CWE-653 Improper Isolation or Compartmentalization

References

Sources

CVE List CVE-2026-95699
NVD CVE-2026-95699

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.

Summary