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Vulnerability record · CVE-2026-4861 · published 26 March 2026

CVE-2026-4861: Wavlink wl-nu516u1 firmware memory buffer overflow vulnerability

Wavlink · Wl Nu516u1 Firmware

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.

7.4 CVSS 4.0 High EPSS 1.1% · top 36.9% CWE-119 · Memory buffer overflowCWE-121 · Stack-based buffer overflow
7.4CVSS 4.0 base score, v2 9.0
1.1%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
4References, 1 tagged exploit
17 Jun 2026Last modified by NVD

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:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

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

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

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Source: NIST National Vulnerability Database (record CVE-2026-4861), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.