CVE-2026-36959

Unrestricted Brute‑Force Login on U‑SPEED N300 Router

Published Apr 30, 2026 CVSS 3.1 · 7.5 High EPSS < 1% KEV · Not listed
Description
U-SPEED N300 router V1.0.0 does not implement rate limiting or account lockout protections on the /api/login endpoint. This allows an attacker on the local network to perform unlimited authentication attempts, enabling brute-force attacks against the administrator account and potential unauthorized access to the router management interface.

Analysis

AI-generated

Technical impact

The U‑SPEED N300 router (firmware v1.0.0) does not enforce rate limiting or lockout mechanisms on its /api/login endpoint. An attacker who can reach the local network can send unlimited authentication attempts, enabling brute‑force attacks against the administrator account and potentially gaining unauthorized access to the router’s management interface.

Affected Systems

U‑SPEED N300 router, firmware version 1.0.0.

Risk and Exploitability

This flaw allows a local attacker to perform unlimited login attempts, raising the likelihood of a successful brute‑force attack. The CVSS score of 7.5 indicates a high severity, and with no public exploit reference and an unavailable EPSS score, the exact exploitation probability remains unknown. The vulnerability could lead to full administrative control of the device. Because the router is not listed in CISA’s KEV catalog, no documented current exploitation is known, but the risk remains high for devices on an unsecured local network.

Remediation

No solution or workaround provided in the CVE record.

OpenCVE Recommended Actions

  • Apply the latest firmware update that includes a login rate‑limiting fix once it is released.
  • Disable or rename the default administrator account and enforce a strong, unique password.
  • Restrict access to the /api/login interface by configuring the router’s firewall or VLAN settings to accept connections only from trusted IP ranges, thereby limiting local network exposure.

Generated by OpenCVE AI on May 2, 2026 at 00:30 UTC.

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
First Time appeared U-speed n300
U-speed n300 Firmware
CPEs cpe:2.3:h:u-speed:n300:-:*:*:*:*:*:*:*
cpe:2.3:o:u-speed:n300_firmware:1.0.0:*:*:*:*:*:*:*
Vendors & Products U-speed n300
U-speed n300 Firmware
Type Values Removed Values Added
Title Unrestricted Brute‑Force Login on U‑SPEED N300 Router
Type Values Removed Values Added
First Time appeared U-speed
U-speed n300 Router
Vendors & Products U-speed
U-speed n300 Router
Type Values Removed Values Added
Weaknesses CWE-307
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N'}

ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description U-SPEED N300 router V1.0.0 does not implement rate limiting or account lockout protections on the /api/login endpoint. This allows an attacker on the local network to perform unlimited authentication attempts, enabling brute-force attacks against the administrator account and potential unauthorized access to the router management interface.
References
Weaknesses
  • CWE-307

    Improper Restriction of Excessive Authentication Attempts

Sources

Status
PUBLISHED
Assigner
mitre
Published
Updated
Jul 5, 2026, 1:32 AM
Reserved
Apr 6, 2026, 12:00 AM
Status
Modified
Published
Apr 30, 2026, 3:16 PM
Modified
Nov 8, 2026, 4:10 PM