Vulnerability · Published Mar 26, 2026 · Assigned by VulDB
CVE-2026-4861Wavlink WL-NU516U1 nas.cgi ftext stack-based overflow
High 8.8
In plain English
A high-severity stack buffer overflow in WL-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 59% of all known vulnerabilities). Ready-made attack tooling exists: public proof-of-concept code.
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.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Wavlink | WL-NU516U1 | 260227 |
Weakness: CWE-121, CWE-119 · Vector: 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
References
- VDB-353192 | Wavlink WL-NU516U1 nas.cgi ftext stack-based overflow vdb-entry, technical-description
- VDB-353192 | CTI Indicators (IOB, IOC, IOA) signature, permissions-required
- Submit #776217 | Wavlink NU516U1 V260227 Stack-based Buffer Overflow third-party-advisory
- https://github.com/Wlz1112/WAVLINK-NU516U1-V260227/blob/main/Content-Length.md exploit