CVE-2026-3703: Wavlink Wl-nu516u1 Firmware buffer overflow (CVSS 9.8)

Description

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.

CVSS 3.1 breakdown

Attack vectorNetwork

Attack complexityLow

Privileges requiredNone

User interactionNone

ScopeUnchanged

ConfidentialityHigh

IntegrityHigh

AvailabilityHigh

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected products

Wavlink Wl-nu516u1 Firmware251208

Remediation

No fixed version is recorded in the NVD data. Check the vendor advisory for the latest guidance.

Patch & vendor advisories

References

https://dl.wavlink.com/firmware/RD/WINSTAR_NU516U1-WO-A-2026-02-27-2fcf6ae-mt7628-squashfs-sysupgrade.binBroken Link
https://github.com/Wlz1112/Wavlink-NU516U1-V251208-/blob/main/ipaddr.mdExploitVendor Advisory
https://github.com/Wlz1112/Wavlink-NU516U1-V251208-/blob/main/ipaddr.md#exp-exploit--pocExploitVendor Advisory
https://vuldb.com/?ctiid.349649Permissions RequiredVDB Entry
https://vuldb.com/?id.349649Third Party AdvisoryVDB Entry
https://vuldb.com/?submit.759226Third Party AdvisoryVDB Entry

Related CVEs

Recent high-severity vulnerabilities sharing a weakness type.

Frequently asked

Is CVE-2026-3703 being actively exploited?

CVE-2026-3703 is not in the CISA KEV catalog. A public exploit reference exists, so treat it as exploitable. Its EPSS exploit probability is 1.26%.

How severe is CVE-2026-3703?

CVE-2026-3703 has a CVSS 3.1 base score of 9.8, rated critical. EPSS estimates a 1.26% probability of exploitation.

Which products are affected by CVE-2026-3703?

Affected products include Wavlink Wl-nu516u1 Firmware.

How do I fix CVE-2026-3703?

Apply the vendor's patch or advisory guidance, then verify no affected versions remain across your devices.

How Secuno handles this

Secuno correlates vulnerabilities like CVE-2026-3703 against the real software inventory on every managed device, every day. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.

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