CVE-2026-4861

Wavlink Wl-nu516u1 Firmware buffer overflow

8.8 HIGHPublic exploitEPSS 1.06%

Published26 Mar 2026

Description

A weakness has been identified in Wavlink WL-NU516U1 260227. This vulnerability affects the function ftext of the file /cgi-bin/nas.cgi. This manipulation of the argument Content-Length causes stack-based buffer overflow. The attack can be initiated remotely. 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.

CVSS 3.1 breakdown

Attack vectorNetwork

Attack complexityLow

Privileges requiredLow

User interactionNone

ScopeUnchanged

ConfidentialityHigh

IntegrityHigh

AvailabilityHigh

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

Affected products

Wavlink Wl-nu516u1 Firmwarem16u1_v260227

Remediation

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

References

https://github.com/Wlz1112/WAVLINK-NU516U1-V260227/blob/main/Content-Length.mdExploitThird Party Advisory
https://vuldb.com/?ctiid.353192Permissions RequiredVDB Entry
https://vuldb.com/?id.353192Third Party AdvisoryVDB Entry
https://vuldb.com/?submit.776217Third Party AdvisoryVDB Entry

Related CVEs

Recent high-severity vulnerabilities sharing a weakness type.

Frequently asked

Is CVE-2026-4861 being actively exploited?

CVE-2026-4861 is not in the CISA KEV catalog. A public exploit reference exists, so treat it as exploitable. Its EPSS exploit probability is 1.06%.

How severe is CVE-2026-4861?

CVE-2026-4861 has a CVSS 3.1 base score of 8.8, rated high. EPSS estimates a 1.06% probability of exploitation.

Which products are affected by CVE-2026-4861?

Affected products include Wavlink Wl-nu516u1 Firmware.

How do I fix CVE-2026-4861?

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-2026-4861 against the real software inventory on every managed device, as each hourly inventory arrives. 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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Data from the NVD, CISA KEV catalog and FIRST EPSS. CVSS 3.1 base score shown where available.