Vulnerability · Published Mar 8, 2026 · Assigned by VulDB
CVE-2026-3703Wavlink NU516U1 login.cgi sub_401A10 out-of-bounds write
Critical 9.8
In plain English
A critical-severity out-of-bounds write in NU516U1 from Wavlink. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.9% (higher than 61% of all known vulnerabilities).
Official 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.
Affected products (as reported)
Weakness: CWE-787, CWE-119 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:P/RL:O/RC:C
References
- VDB-349649 | Wavlink NU516U1 login.cgi sub_401A10 out-of-bounds write vdb-entry, technical-description
- VDB-349649 | CTI Indicators (IOB, IOC, IOA) signature, permissions-required
- Submit #759226 | Wavlink NU516U1 V251208 Stack-based Buffer Overflow third-party-advisory
- https://github.com/Wlz1112/Wavlink-NU516U1-V251208-/blob/main/ipaddr.md related
- https://github.com/Wlz1112/Wavlink-NU516U1-V251208-/blob/main/ipaddr.md#exp-exploit--poc exploit
- https://dl.wavlink.com/firmware/RD/WINSTAR_NU516U1-WO-A-2026-02-27-2fcf6ae-mt7628-squashfs-sysupgrade.bin patch