CVE-2026-31851

Administrative compromise via unrestricted password guessing

Published Mar 23, 2026 · Updated Mar 23, 2026

Authentication brute forcing in Nexxt Solutions Nebula 300+ 12.01.01.37 and earlier allows remote attackers to guess admin credentials. Its web authentication interface accepts unlimited credential-validation requests without rate limiting or failed-login lockout. An unauthenticated attacker must reach the router from an adjacent network; successful guessing grants administrative access.

CVSS severity7.7
High
EPSS probability0.33%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Authentication brute forcing in Nexxt Solutions Nebula 300+ 12.01.01.37 and earlier allows remote attackers to guess admin credentials. Its web authentication interface accepts unlimited credential-validation requests without rate limiting or failed-login lockout. An unauthenticated attacker must reach the router from an adjacent network; successful guessing grants administrative access.

The record

CVE
CVE-2026-31851
Published
Mar 23, 2026
Updated
Mar 23, 2026
Vendor
Nexxt Solutions
Product
Nebula 300+
Classifications
CWE-307, T1110.001
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 23, 2026CVE publishedPublication date reported by the CVE source.
  2. Mar 23, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=<= 12.01.01.37

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

Nexxt Solutions · Nebula 300+version=<= 12.01.01.37

Published CVSS scores

7.7TuranSecCVSS:4.0/AV:A/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
9.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectoradjacent
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-307Improper Restriction of Excessive Authentication Attempts
T1110.001Password Guessing

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo