Security readout for executives and security teams
Plain-English summary
Nebula 300+ devices running firmware 12.01.01.37 or earlier allow unrestricted login attempts. A nearby attacker could repeatedly guess administrator credentials, potentially gaining control of the device and compromising its confidentiality, integrity, and availability. The supplied sources do not identify a patched version or confirm exploitation in the wild.
Executive priority
Prioritize affected devices with authentication interfaces accessible from untrusted networks. Apply access restrictions and credential hardening promptly while seeking vendor remediation guidance. Treat evidence of repeated login failures or unexpected administrator access as an incident requiring investigation. No active exploitation is established by the supplied evidence.
Technical view
CVE-2026-31851 is CWE-307: authentication interfaces lack rate limiting and account lockout. CVSS 4.0 rates it 7.7 High, with adjacent-network access, high attack complexity, no prior privileges, and no user interaction. Successful credential guessing could produce high confidentiality, integrity, and availability impacts on the vulnerable device.
Likely exposure
Exposure is limited to Nexxt Solutions Nebula 300+ firmware through 12.01.01.37. Risk is greatest where authentication interfaces are reachable from adjacent or otherwise untrusted networks, especially when administrative credentials are weak or reused. The bundle does not establish internet exposure or affect other Nexxt products.
Exploitation context
The CVSS vector requires adjacent-network access and rates attack complexity high. Neither CISA KEV status nor the supplied sources confirm active exploitation. The weakness removes attempt limits, but successful compromise still depends on reaching an authentication interface and correctly guessing valid credentials.
Researcher notes
The record identifies missing rate limiting and lockout but does not specify every affected endpoint, default credential behavior, a patched firmware version, or vendor-prescribed mitigation. Validation should remain non-destructive: confirm version, interface reachability, controls, and logs. Do not infer that firmware newer than 12.01.01.37 is fixed without vendor confirmation.
Mitigation direction
- Confirm firmware versions and check Nexxt Solutions guidance for an official correction or newer release.
- Restrict administrative interfaces to trusted management networks and authorized administrators.
- Use long, unique administrative credentials and replace weak, default, or reused passwords.
- Disable unnecessary authentication interfaces or remote administration where operationally feasible.
- Monitor authentication activity for repeated failures or unusual administrative access.
Validation and detection
- Inventory Nebula 300+ devices and record their installed firmware versions.
- Flag devices running version 12.01.01.37 or earlier for remediation review.
- Verify administrative interfaces are inaccessible from untrusted or unnecessary network segments.
- Review authentication logs for repeated failures, password guessing patterns, and unexpected successful logins.
- Confirm credentials are unique and vendor guidance has been checked without conducting brute-force testing.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-307: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCredential and access behavior lookup
The CVE wording references authentication or credential exposure, so valid-account and credential-access review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2026-31851 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- High
- CVSS
- 7.7 (4.0)
- Known Exploited
- No
- Published
Vector: CVSS:4.0/AV:A/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
SSVC decision data
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:4.0/AV:A/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N——TuranSecVulnerability scoring details
Base CVSS 4.0 score
7.7HighVector: CVSS:4.0/AV:A/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
Source materials
- CVE List V5 sourceCVE List V5
- https://www.nexxtsolutions.com/connectivity/internal-products/ARN02304U6/CVE reference, TuranSec · third-party-advisory
- https://nexxt-connectivity-frontend.s3.amazonaws.com/media/docs/Nebula300+_v12.01.01.37.zipCVE reference, TuranSec · third-party-advisory
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Improper Restriction of Excessive Authentication Attempts
Improper Restriction of Excessive Authentication Attempts represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.