What is CVE-2026-3703?

CVE-2026-3703 is a critical-severity vulnerability in Wavlink Nu516u1, classified under Improper Restriction of Operations within the Bounds of a Memory Buffer. CVSS score: 9.8/10. Published 2026-03-08.

How severe is CVE-2026-3703?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Buffer overflow in Wavlink Nu516u1

CVE-2026-3703

A flaw has been found in Wavlink NU516U1 251208. This affects the function sub_401A10 of the file /cgi-bin/login.cgi. Executing a manipulation of the argument ipaddr can lead to out-of-bounds write. The attack may be performed from remote. The exploit has been published and may be used. Upgrading the affected component is recommended. The vendor was contacted early, responded in a very professional manner and quickly released a fixed version of the affected product.

Vulnerability class: Buffer Overflow

Published 2026-03-08 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.009 (58.2th percentile), scored 2026-11-02.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 58th percentile — 58.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.012 · newest: 0.009 · change: -0.004

Affected products

Wavlink Nu516u1 — versions 251208
Wavlink Wl-Nu516u1
Wavlink Wl-Nu516u1 Firmware — versions 251208

Weakness classification (CWE)

References

vuldb.com/ (technical-description, VDB Entry, Third Party Advisory, vdb-entry)
vuldb.com/ (signature, Permissions Required, permissions-required, VDB Entry)
vuldb.com/ (VDB Entry, Third Party Advisory, third-party-advisory)
github.com/Wlz1112/Wavlink-NU516U1-V251208-/blob/main/ipaddr.md (related, Exploit, Vendor Advisory)
github.com/Wlz1112/Wavlink-NU516U1-V251208-/blob/main/ipaddr.md (Exploit, exploit, Vendor Advisory)
dl.wavlink.com/firmware/RD/WINSTAR_NU516U1-WO-A-2026-02-27-2fcf6ae-mt7628-squas… (patch, Broken Link)

Frequently asked questions

What is CVE-2026-3703?: CVE-2026-3703 is a critical-severity vulnerability in Wavlink Nu516u1, classified under Improper Restriction of Operations within the Bounds of a Memory Buffer. CVSS score: 9.8/10. Published 2026-03-08.
How severe is CVE-2026-3703?: Critical severity. CVSS v3 base score is 9.8 out of 10.