CVE-2026-31847: Hidden functionality in the /goform/setSysTools endpoint in Nexxt Solutions Nebula 300+ firmware through versi

Q: How do I fix CVE-2026-31847?

nebula300plus firmware: upgrade to newer than 12.01.01.37. Exact commands for each OS are on this page.

Q: Is CVE-2026-31847 being exploited?

CVE-2026-31847 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-31847 affect?

CVE-2026-31847 affects nebula300plus firmware. Severity is high (CVSS 8.8). Hidden functionality in the /goform/setSysTools endpoint in Nexxt Solutions Nebula 300+ firmware through version 12.01.01.37 allows remote enablement of a Telnet service. By sending a crafted POST request with parameters such as telnetManag

This month

HIGH 8.8UPGRADE

CVE-2026-31847 is a high-severity flaw (CVSS 8.8) affecting nebula300plus firmware. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Hidden functionality in the /goform/setSysTools endpoint in Nexxt Solutions Nebula 300+ firmware through version 12.01.01.37 allows remote enablement of a Telnet service. By sending a crafted POST request with parameters such as telnetManageEn=true and telnetPwd, an authenticated attacker can activate a Telnet service on port 23.

Why this priority

High severity

A fixed release or distro patch exists.

Risk facts

CVSS score	8.8 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	0.4% (top 61%)
CISA exploited list	No
Weakness	CWE-912
Published	2026-03-23
Last modified	2026-08-10

Publisher (CNA): TuranSec · Vendor: nexxtsolutions

Last updated 2026-08-10 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-03-23 13:16 UTCPublished CVE record published
2026-08-10 12:17 UTCUpdated Record last modified

nexxtsolutions nebula300plus firmware UPGRADE

Affected: <= 12.01.01.37

Fixed in: newer than 12.01.01.37

Safe to downgrade to: no unaffected older release

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-31847?

nebula300plus firmware: upgrade to newer than 12.01.01.37. Exact commands for each OS are on this page.

Is CVE-2026-31847 being exploited?

CVE-2026-31847 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-31847 affect?

CVE-2026-31847 affects nebula300plus firmware. Severity is high (CVSS 8.8). Hidden functionality in the /goform/setSysTools endpoint in Nexxt Solutions Nebula 300+ firmware through version 12.01.01.37 allows remote enablement of a Telnet service. By sending a crafted POST request with parameters such as telnetManag

How urgent is CVE-2026-31847?

Priority 40/100. High severity

Related CVEs

CVE-2026-31848 CRITICAL 9.8 UPGRADE Nexxt Solutions Nebula 300+ firmware through version 12.01.01.37 uses the ecos_pw cookie for authentication, w
CVE-2026-31851 CRITICAL 9.8 UPGRADE Nexxt Solutions Nebula 300+ firmware through version 12.01.01.37 does not implement rate limiting or account l
CVE-2026-31850 MEDIUM 4.9 UPGRADE Nexxt Solutions Nebula 300+ firmware through version 12.01.01.37 stores sensitive information, including admin
CVE-2026-31849 MEDIUM 6.5 UPGRADE Nexxt Solutions Nebula 300+ firmware through version 12.01.01.37 does not implement CSRF protections on state-

References

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