How severe is CVE-2026-31851?

CVE-2026-31851 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2026-31851 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (25th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-31851?

CVE-2026-31851 affects Nexxtsolutions Nebula300plus Firmware. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-31851?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

Does CVE-2026-31851 have an EU (EUVD) identifier?

Yes. CVE-2026-31851 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-14421.

When was CVE-2026-31851 published?

CVE-2026-31851 was published on 2026-03-23 and last updated on 2026-06-17.

CVE-2026-31851

CVE-2026-31851 is a critical-severity vulnerability in Nexxtsolutions Nebula300plus Firmware with a CVSS 3.x base score of 9.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-307.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v4: 7.7
EPSS exploit prediction: 0% (25th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-14421
Weakness: CWE-307
Affected product: Nexxtsolutions Nebula300plus Firmware
Published: 2026-03-23
Last modified: 2026-06-17

Description

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 rely on credential validation, enabling brute-force attacks to guess administrative credentials without restriction.

Frequently asked questions

What is 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 rely on credential validation, enabling brute-force attacks to guess administrative credentials without restriction.
How severe is CVE-2026-31851?: CVE-2026-31851 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-31851 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (25th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-31851?: CVE-2026-31851 affects Nexxtsolutions Nebula300plus Firmware. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-31851?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
Does CVE-2026-31851 have an EU (EUVD) identifier?: Yes. CVE-2026-31851 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-14421.
When was CVE-2026-31851 published?: CVE-2026-31851 was published on 2026-03-23 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:o:nexxtsolutions:nebula300plus_firmware:*:*:*:*:*:*:*:*

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CVE-2026-31848 — Critical (CVSS 9.8): Nexxt Solutions Nebula 300+ firmware through version 12.01.01.37 uses the ecos_pw cookie for authentication, which…
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