CVE-2026-4861 Details
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.
A stack-based buffer overflow vulnerability has been identified in the Wavlink NU516U1 router, specifically in the latest firmware version 260227. The issue arises in the 'ftext' function of the '/cgi-bin/nas.cgi' component, where the program fails to properly validate the 'Content-Length' header in HTTP POST requests. This oversight allows attackers to send excessively long data that overflows the buffer, overwrites the return address, and hijacks the execution flow, potentially leading to remote code execution.
Metrics
CVSS 4.0 Severity and Vector Strings:
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
CISA-ADP
Assessed Mar 26, 2026References to Advisories, Solutions, and Tools
By selecting these links, you will be leaving this site. These are references gathered from the official CVE record and are not endorsed by Volerion.
| URL | Source(s) | Tag(s) |
|---|---|---|
| https://github.com/Wlz1112/WAVLINK-NU516U1-V260227/blob/main/Content-Length.md | [email protected] | ExploitThird Party Advisory |
| https://vuldb.com/?ctiid.353192 | [email protected] | Permissions RequiredVDB Entry |
| https://vuldb.com/?id.353192 | [email protected] | Third Party AdvisoryVDB Entry |
| https://vuldb.com/?submit.776217 | [email protected] | Third Party AdvisoryVDB Entry |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-119 | Improper Restriction of Operations within the Bounds of a Memory Buffer | [email protected] |
| CWE-121 | Stack-based Buffer Overflow | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| wavlink wl-nu516u1 firmware | m16u1_v260227 |
CPE
Remediation
| |
| wavlink wl-nu516u1 | All versions |
CPE
Remediation
| |
Change History
4 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jun 17, 2026 | CVE Modified | [email protected] |
| Jun 17, 2026 | CVE Modified | CISA-ADP |
| Apr 30, 2026 | Initial Analysis | [email protected] |
| Mar 26, 2026 | New CVE Received | [email protected] |