CVE-2026-31848
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedNexxt Solutions Nebula 300+ firmware through version 12.01.01.37 uses the ecos_pw cookie for authentication, which contains Base64-encoded credential data combined with a static suffix. Because the encoding is reversible and lacks integrity protection, an attacker can reconstruct or forge a valid cookie value without proper authentication.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceThe Nexxt Solutions Nebula 300+ router firmware uses a cookie (ecos_pw) for authentication that contains Base64-encoded credentials combined with a static suffix. Because the encoding is reversible and lacks cryptographic integrity protection (such as HMAC or signing), an attacker can Base64-decode the cookie, modify the credential portion, re-encode it with the static suffix, and gain unauthorized administrative access to the device without knowing valid credentials.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data<= 12.01.01.37CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
-
Identify the router firmware versionAccess the router's administrative web interface and navigate to the Status or System Information page to view the firmware version. Alternatively, check the device label or use the command 'cat /proc/version' if you have SSH/telnet access to the router's underlying Linux system.Affected if The firmware version is 12.01.01.37 or lower.
-
Confirm the device model is Nebula 300+Verify the exact model number displayed in the router's admin interface under Status or System Information. The vulnerability specifically affects the Nebula300plus model.Affected if The device is a Nexxt Solutions Nebula 300+ (Nebula300plus) router.
-
Inspect authentication cookie structureLog into the router's web interface and use browser developer tools (F12) or a packet capture tool to examine the cookies sent after authentication. Look for a cookie named 'ecos_pw'. If present, capture its value and attempt to Base64-decode it to check if it follows the pattern of encoded credentials with a static suffix.Affected if The 'ecos_pw' cookie exists and contains Base64-encoded data that can be decoded and modified, then re-encoded to maintain valid authentication.
-
Check for external accessibility of admin interfaceVerify whether the router's administrative web interface (typically ports 80 or 443) is exposed to the internet by attempting to access the router's WAN IP from an external network, or by reviewing firewall rules on the router.Affected if The router's admin interface is reachable from untrusted networks (the internet), which would allow remote exploitation of this vulnerability.
You are affected if you are running Nexxt Solutions Nebula 300+ firmware version 12.01.01.37 or lower AND your router's admin interface is accessible to untrusted networks.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
From vendor dataApply any vendor firmware update when available; until then, restrict network access to the router's administrative interface using firewall rules or ACLs to prevent external attackers from reaching the authentication endpoints.
- Consultation8.0 h
- Implementation24.0 h
- Testing12.0 h
- Review / QA8.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $14,656.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-31848 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-31848 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.
A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.
- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
- No spam, self-promotion, credentials, or personal data