What is CVE-2026-31851?

CVE-2026-31851 is a critical-severity vulnerability in Nexxt Solutions Nebula 300+, classified under Improper Restriction of Excessive Authentication Attempts. CVSS score: 9.8/10. Published 2026-03-23.

How severe is CVE-2026-31851?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Vulnerability in Nexxt Solutions Nebula 300+

CVE-2026-31851

Nexxt Solutions Nebula 300+ firmware through version 12.01.01.37 does not implement rate limiting or account lockout mechanisms on authentication interfaces. An attacker can perform unlimited authentication attempts against endpoints that…

EPSS: 0.001 (23.8th percentile) — read the EPSS interpretation.

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.

Affected products

Nexxt Solutions Nebula 300+ — versions <= 12.01.01.37
Nexxtsolutions Nebula300plus
Nexxtsolutions Nebula300plus_firmware

Weakness classification (CWE)

CWE-307 — Improper Restriction of Excessive Authentication Attempts

References

309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c (Product)
309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c (Product)

Frequently asked questions

What is CVE-2026-31851?: CVE-2026-31851 is a critical-severity vulnerability in Nexxt Solutions Nebula 300+, classified under Improper Restriction of Excessive Authentication Attempts. CVSS score: 9.8/10. Published 2026-03-23.
How severe is CVE-2026-31851?: Critical severity. CVSS v3 base score is 9.8 out of 10.