Vulnerability details

CVE-2026-4861

Wavlink WL-NU516U1

Wavlink WL-NU516U1 nas.cgi ftext stack-based overflow

CVSS 4.0

8.7High

Official 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 scores

Score	Version	Source	Vector
8.7High	4.0	CVEProject cvelistV5 (CNA) (VulDB)	`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`
8.8High	3.1	CVEProject cvelistV5 (CNA) (VulDB)	`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:P/RL:X/RC:R`
8.8High	3.0	CVEProject cvelistV5 (CNA) (VulDB)	`CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:P/RL:X/RC:R`
9.0High	2.0	CVEProject cvelistV5 (CNA) (VulDB)	`AV:N/AC:L/Au:S/C:C/I:C/A:C/E:POC/RL:ND/RC:UR`

Affected products

Vendor	Product	Versions	Source
Wavlink	WL-NU516U1	260227	CVEProject cvelistV5 (CNA)

References and advisories

https://vuldb.com/?id.353192 vdb-entrytechnical-description
https://vuldb.com/?ctiid.353192 signaturepermissions-required
https://vuldb.com/?submit.776217 third-party-advisory
https://github.com/Wlz1112/WAVLINK-NU516U1-V260227/blob/main/Content-Length.md exploit

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Details

Published: 2026-03-26
Last updated: 2026-03-26
State: Published
Assigner (CNA): VulDB

Exploit prediction (EPSS)

0.86%

Probability of exploitation in 30 days

58.8%

Percentile (among all CVEs)

SSVC assessment (CISA)

Automatable: No
Exploitation: Proof of concept
Technical impact: Total

Weaknesses (CWE)

CWE-121
Stack-based Buffer Overflow
CWE-119
Memory Corruption