Description
A vulnerability was found in Wavlink WL-NU516U1 708c073-mt7628. This impacts the function change_password of the file nas.cgi. The manipulation of the argument User1Passwd results in stack-based buffer overflow. The attack can be executed remotely. The exploit has been made public and could be used. The affected component should be upgraded. The vendor was contacted early, responded in a very professional manner and quickly released a fixed version of the affected product.
Published: 2026-08-03
Score: 9.3 Critical
EPSS: n/a
KEV: No
Impact: n/a
Action: n/a
AI Analysis

Impact

The vulnerability resides in the change_password function of the nas.cgi script on the Wavlink WL‑NU516U1 router running firmware 708c073‑mt7628. By manipulating the User1Passwd argument, an attacker can overflow a stack buffer, potentially gaining arbitrary code execution or causing denial of service. This is a classic stack overflow weakness associated with CWE‑119 and CWE‑121.

Affected Systems

The flaw affects only the Wavlink WL‑NU516U1 model with firmware build 708c073‑mt7628. No other versions are listed as impacted. The vulnerable code lies within the device’s management interface exposed remotely via nas.cgi.

Risk and Exploitability

The CVSS score of 9.3 reflects critical severity. EPSS data is not available, yet the exploit is publicly documented and can be executed remotely through the web interface. The vulnerability is not currently listed in the CISA KEV catalog, but the combination of high CVSS, remote exploitability, and existence of a public exploit demands urgent remediation. The attack vector is inferred to be the device’s web management portal, where a crafted payload targeting the User1Passwd field can trigger the overflow.

Generated by OpenCVE AI on August 3, 2026 at 08:34 UTC.

Remediation

No vendor fix or workaround currently provided.

OpenCVE Recommended Actions

  • Update the device to the latest firmware version released by Wavlink that contains the fix for the change_password buffer overflow.
  • If an immediate firmware update is not available, isolate the web management interface using a firewall or VPN so that only trusted administrators can reach it, thereby limiting exposure to the vulnerable endpoint.
  • As a temporary measure, disable remote password change functionality or apply firewall rules to block access to nas.cgi from untrusted networks.

Generated by OpenCVE AI on August 3, 2026 at 08:34 UTC.

Tracking

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Advisories

No advisories yet.

History

Mon, 03 Aug 2026 08:00:00 +0000

Type Values Removed Values Added
First Time appeared Wavlink wl-nu516u1
Vendors & Products Wavlink wl-nu516u1

Mon, 03 Aug 2026 06:45:00 +0000

Type Values Removed Values Added
Description A vulnerability was found in Wavlink WL-NU516U1 708c073-mt7628. This impacts the function change_password of the file nas.cgi. The manipulation of the argument User1Passwd results in stack-based buffer overflow. The attack can be executed remotely. The exploit has been made public and could be used. The affected component should be upgraded. The vendor was contacted early, responded in a very professional manner and quickly released a fixed version of the affected product.
Title Wavlink WL-NU516U1 nas.cgi change_password stack-based overflow
First Time appeared Wavlink
Wavlink wl-nu516u1 Firmware
Weaknesses CWE-119
CWE-121
CPEs cpe:2.3:o:wavlink:wl-nu516u1_firmware:*:*:*:*:*:*:*:*
Vendors & Products Wavlink
Wavlink wl-nu516u1 Firmware
References
Metrics cvssV2_0

{'score': 10, 'vector': 'AV:N/AC:L/Au:N/C:C/I:C/A:C/E:POC/RL:OF/RC:C'}

cvssV3_0

{'score': 9.8, 'vector': 'CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:P/RL:O/RC:C'}

cvssV3_1

{'score': 9.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:P/RL:O/RC:C'}

cvssV4_0

{'score': 9.3, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P'}

Subscriptions

Wavlink Wl-nu516u1 Wl-nu516u1 Firmware
cve-icon MITRE

Status: PUBLISHED

Assigner: VulDB

Published:

Updated: 2026-08-03T06:30:10.498Z

Reserved: 2026-08-02T20:33:42.866Z

Link: CVE-2026-18589

cve-icon Vulnrichment

No data.

cve-icon NVD

No data.

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-08-03T07:45:17Z

Weaknesses
  • CWE-119

    Improper Restriction of Operations within the Bounds of a Memory Buffer

  • CWE-121

    Stack-based Buffer Overflow