CVE-2026-3703: Wavlink NU516U1 · Out-of-bounds Write
Affects Wavlink NU516U1Source CVE Database V5
Public exploit available · CVSS 9.3 Critical.
Data as of 29 Oct 2026, 19:04 UTC
- EPSS
- 0.8% chance of exploitation in 30 days – higher than 58% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:PExploitation evidence
Disclosed: evidence found.
CVE published 8 Mar 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: evidence found.
CVSS exploit maturity: proof of concept public
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), CVSS vector, the Metasploit, Exploit-DB and nuclei-templates index as of 29 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| WavlinkNU516U1 | Affected
| Fixed in– |
GitHubwavlink/NU516U1pkg:github/wavlink/NU516U1Other threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
To mitigate CVE-2026-3703, organizations should immediately upgrade the Wavlink NU516U1 firmware to the vendor’s fixed version as soon as it becomes available. Until the patch is applied, network administrators should restrict access to the router’s management interface, ideally limiting it to trusted internal networks and blocking remote access from untrusted sources. Deploy network-level intrusion detection and prevention systems to monitor for suspicious CGI requests targeting the /cgi-bin/login.cgi endpoint. Implement strict network segmentation to isolate vulnerable devices from critical assets. Regularly audit device firmware versions and maintain an inventory of network hardware to ensure timely patch management. Additionally, consider disabling unnecessary services or CGI scripts if possible to reduce the attack surface. Monitoring vendor advisories and threat intelligence feeds for exploit developments is also recommended to respond quickly to emerging threats.
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.
References
- vuldb.com (opens in a new tab)
- vuldb.com (opens in a new tab)
- vuldb.com (opens in a new tab)
- github.com/Wlz1112/Wavlink-NU516U1-V251208-/blob/main/ipaddr.md (opens in a new tab)
- github.com/Wlz1112/Wavlink-NU516U1-V251208-/blob/main/ipaddr.md (opens in a new tab)
- dl.wavlink.com/firmware/RD/WINSTAR_NU516U1-WO-A-2026-02-27-2fcf6ae-mt7628-squashfs-sysupgrade.bin (opens in a new tab)