CVE-2026-2566Public exploitNetwork attack vector

Authenticated code execution via unbounded firmware URL escaping

Published Feb 16, 2026 · Updated Feb 16, 2026

Stack-based buffer overflow in Wavlink WL-NU516U1 firmware 130 and 260 allows remote authenticated users to execute code via firmware_url. The OTA handler sub_406194 passes the URL to sub_40CCA0, which doubles its length by prefixing each character with a backslash and appends it with strcat to a 260-byte stack buffer without checking the destination boundary. A valid management session is required; a long value can overwrite the saved return address, causing a crash or redirecting device execution.

CVSS severity7.2
High
EPSS probability0.49%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stack-based buffer overflow in Wavlink WL-NU516U1 firmware 130 and 260 allows remote authenticated users to execute code via firmware_url. The OTA handler sub_406194 passes the URL to sub_40CCA0, which doubles its length by prefixing each character with a backslash and appends it with strcat to a 260-byte stack buffer without checking the destination boundary. A valid management session is required; a long value can overwrite the saved return address, causing a crash or redirecting device execution.

The record

CVE
CVE-2026-2566
Published
Feb 16, 2026
Updated
Feb 16, 2026
Vendor
Wavlink
Product
WL-NU516U1
Classifications
CWE-119, CWE-121, T1190
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Feb 16, 2026CVE publishedPublication date reported by the CVE source.
  2. Feb 16, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=130
  2. Affected versionversion=260

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Wavlink · WL-NU516U1version=130; version=260

Published CVSS scores

7.2NVDCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
8.3NVDAV:N/AC:L/Au:M/C:C/I:C/A:C
7.3NVDCVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-119Memory Corruption
CWE-121Stack-based Buffer Overflow
T1190Exploit Public-Facing Application

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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