Memory Buffer Bounds ErrorWeakness · CWE-119

CVE-2026-5566

HIGH · 8.8 CVSS v3.1 Published 2026-04-05
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
94/100
Remediation priority · Urgent
Remotely reachable Zero-click

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 · unedited
A vulnerability was detected in UTT HiPER 1250GW up to 3.2.7-210907-180535. This affects the function strcpy of the file /goform/formNatStaticMap. Performing a manipulation of the argument NatBind results in buffer overflow. Remote exploitation of the attack is possible. The exploit is now public and may be used.

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 · moderate confidence

A buffer overflow vulnerability exists in the UTT HiPER 1250GW router firmware (up to version 3.2.7-210907-180535) in the /goform/formNATStaticMap web form handler. The unsafe strcpy function is used to process the NatBind HTTP parameter without bounds checking, allowing remote attackers to overflow a fixed-size buffer via crafted input.

MitigationReplace the unsafe strcpy call with bounds-safe functions (strncpy, strlcpy, or snprintf) and implement input validation on the NatBind parameter. If a patched firmware version is available, upgrade immediately; otherwise, restrict access to the router's web interface via network segmentation or firewall rules.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

CVSS 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
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:L/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 checks

Work through these to decide whether this CVE applies to you.

  1. Identify router firmware version
    Access the router's web administration interface and navigate to the Status or System Information page to view the firmware version, or use the command 'cat /proc/version' or 'nvram get firmware_version' via telnet/SSH if available. Compare the displayed version to the affected range (versions up to and including 3.2.7-210907-180535).
    Affected if The firmware version is 3.2.7-210907-180535 or earlier.
  2. Confirm NAT static mapping feature is enabled
    Log into the router web interface and check the NAT or Port Forwarding settings section for any configured static mapping entries. Look for a feature labeled 'NAT Static Map', 'Static NAT', or 'One-to-One NAT' in the forwarding configuration.
    Affected if NAT static mapping is configured or enabled in the router settings.
  3. Verify web management interface accessibility
    Check if the router's web interface on ports 80/443 is reachable from network segments outside the trusted local network. Use a port scanner or browser access test from an external IP or untrusted network segment.
    Affected if The router web management interface is accessible from untrusted networks.
  4. Inspect NAT static mapping configuration file
    If telnet/SSH access is available, examine /etc/config/nat or the NVRAM settings for 'NatBind' or 'static_nat' entries using 'nvram show | grep -i nat'.
    Affected if The NatBind parameter is present in the configuration and contains user-controlled input.

The router is affected if it runs firmware version 3.2.7-210907-180535 or earlier AND has NAT static mapping enabled with the web interface accessible to potential attackers.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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 data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Replace the unsafe strcpy call with bounds-safe functions (strncpy, strlcpy, or snprintf) and implement input validation on the NatBind parameter. If a patched firmware version is available, upgrade immediately; otherwise, restrict access to the router's web interface via network segmentation or firewall rules.

Have this fixed Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing6.0 h
  • Review / QA3.0 h
15.0 hours of engineering $2,560
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Scan for this in your stack

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-5566 in production — separate from our analysis above.

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What this is

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.

What belongs here
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  • Version or environment caveats, and links to real fixes
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