Improper Authorization of Break Signal Commands in Devices

published 2026-06-16 4 mo ago modified 2026-06-17 4 mo ago also EUVD-2026-37119

cvss: 6.9; version 4.0, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.3%; EPSS 0.3% chance of exploitation in 30 days, percentile 21%
public exploits: 0; none known

A denial-of-service vulnerability exists in NPort devices because of improper access control on the command port. The command interface does not properly validate whether a sender is associated with a valid data port session before accepting break signal commands. A remote attacker with network access can send crafted requests to disrupt serial communication for an active user session.

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: partial
Assessed: 4 mo ago (2026-06-16)

Exploit prediction

0.29% chance of exploitation in the next 30 days, higher than 21% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	4.0	6.9	CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:L
CNA	4.0	6.9	CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:L/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

Moxa NPort 6000 Series
Moxa CN2600 Series

Classification

Weakness

CWE-862 Missing Authorization

References

moxa.com /en/support/product-support/security-advisory/mpsa-262370-cve-2026-10831-improper-authorization-vulnerability-
vendor-advisory

Sources

CVE List CVE-2026-10831
NVD CVE-2026-10831

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Summary